Flexible self-capacitance and mutual capacitance touch sensing system architecture

ABSTRACT

A switching circuit is disclosed. The switching circuit can comprise a plurality of pixel mux blocks, each of the pixel mux blocks configured to be coupled to a respective touch node electrode on a touch sensor panel, and each of the pixel mux blocks including logic circuitry. The switching circuit can also comprise a plurality of signal lines configured to be coupled to sense circuitry, at least one of the signal lines configured to transmit a touch signal from one of the respective touch node electrodes to the sense circuitry. The logic circuitry in each pixel mux block of the plurality of pixel mux blocks can be configured to control the respective pixel mux block so as to selectively couple the respective pixel mux block to any one of the plurality of signal lines.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. application Ser. No.15/009,774, filed Jan. 28, 2016 and published on Aug. 4, 2016 as U.S.Publication No. 2016-0224177, which claims benefit of U.S. ProvisionalApplication No. 62/111,077, filed Feb. 2, 2015, the contents of whichare hereby incorporated by reference in their entirety for all purposes.

FIELD OF THE DISCLOSURE

This relates generally to touch sensor panels that are integrated withdisplays, and more particularly, to a flexible touch and/or pen sensingsystem architecture for self-capacitance and mutual capacitanceintegrated touch screens.

BACKGROUND OF THE DISCLOSURE

Many types of input devices are presently available for performingoperations in a computing system, such as buttons or keys, mice,trackballs, joysticks, touch sensor panels, touch screens and the like.Touch screens, in particular, are becoming increasingly popular becauseof their ease and versatility of operation as well as their decliningprice. Touch screens can include a touch sensor panel, which can be aclear panel with a touch-sensitive surface, and a display device such asa liquid crystal display (LCD) that can be positioned partially or fullybehind the panel so that the touch-sensitive surface can cover at leasta portion of the viewable area of the display device. Touch screens canallow a user to perform various functions by touching the touch sensorpanel using a finger, stylus or other object at a location oftendictated by a user interface (UI) being displayed by the display device.In general, touch screens can recognize a touch and the position of thetouch on the touch sensor panel, and the computing system can theninterpret the touch in accordance with the display appearing at the timeof the touch, and thereafter can perform one or more actions based onthe touch. In the case of some touch sensing systems, a physical touchon the display is not needed to detect a touch. For example, in somecapacitive-type touch sensing systems, fringing electrical fields usedto detect touch can extend beyond the surface of the display, andobjects approaching near the surface may be detected near the surfacewithout actually touching the surface.

Capacitive touch sensor panels can be formed by a matrix ofsubstantially transparent or non-transparent conductive plates made ofmaterials such as Indium Tin Oxide (ITO). It is due in part to theirsubstantial transparency that capacitive touch sensor panels can beoverlaid on a display to form a touch screen, as described above. Sometouch screens can be formed by at least partially integrating touchsensing circuitry into a display pixel stackup (i.e., the stackedmaterial layers forming the display pixels).

SUMMARY OF THE DISCLOSURE

Some capacitive touch sensor panels can be formed by a matrix ofsubstantially transparent or non-transparent conductive plates made ofmaterials such as Indium Tin Oxide (ITO), and some touch screens can beformed by at least partially integrating touch sensing circuitry into adisplay pixel stackup (i.e., the stacked material layers forming thedisplay pixels). The conductive plates can be electrically connected tosense circuitry for sensing touch events on the touch screen. In someexamples, many different types of scans can be implemented on a touchscreen, and thus it can be beneficial for the architecture of the touchscreen to have sufficient flexibility to allow for implementation ofthese different types of scans on the touch screen. Further, in someexamples, a touch screen can include a relatively large number ofconductive plates on which touch events can be sensed. The examples ofthe disclosure provide various touch sensing architectures that arespace-efficient and flexible.

BRIEF DESCRIPTION OF THE DRAWINGS

FIGS. 1A-1C illustrate an example mobile telephone, an example mediaplayer, and an example portable computing device that each include anexemplary touch screen according to examples of the disclosure.

FIG. 2 is a block diagram of an exemplary computing system thatillustrates one implementation of an example touch screen according toexamples of the disclosure.

FIGS. 3A-3C illustrate exemplary sensor circuits according to examplesof the disclosure.

FIG. 4 illustrates an example configuration in which common electrodescan form portions of the touch sensing circuitry of a touch sensingsystem.

FIG. 5A illustrates an exemplary touch node electrode routingconfiguration in which touch node traces can be routed directly fromtouch node electrodes to sense circuitry according to examples of thedisclosure.

FIG. 5B illustrates an exemplary touch node electrode routingconfiguration that includes switching circuits according to examples ofthe disclosure.

FIG. 6A illustrates exemplary display, touch and pen frames according toexamples of the disclosure.

FIG. 6B illustrates exemplary details of a time period in a touch frameaccording to examples of the disclosure.

FIG. 6C illustrates exemplary details of various time periods in a touchframe according to examples of the disclosure.

FIG. 6D illustrates an exemplary configuration of touch node electrodesin various regions of a touch screen while another region is beingscanned in a self-capacitance configuration as described with referenceto FIG. 6C.

FIGS. 7A-7C illustrate exemplary touch screen configurations in whichsome supernodes on the touch screen can extend across multiple switchingcircuits according to examples of the disclosure.

FIG. 8A illustrates an exemplary touch screen configuration, includingexemplary interconnect lines that can be part of switching circuitsaccording to examples of the disclosure.

FIG. 8B illustrates an exemplary touch screen configuration havingshared interconnect lines across switching circuits according toexamples of the disclosure.

FIG. 8C illustrates an exemplary switching circuit configuration inwhich the switching circuits include three sets of interconnect linesaccording to examples of the disclosure.

FIG. 8D illustrates an exemplary switching circuit configuration havinga reduced number of interconnect lines according to examples of thedisclosure.

FIG. 9A illustrates an exemplary memory-based switching circuitconfiguration according to examples of the disclosure.

FIG. 9B illustrates an exemplary numbering of touch node electrodesaccording to examples of the disclosure.

FIG. 9C illustrates an exemplary logical block diagram for a switchingcircuit including PMB logic distributed across the switching circuitaccording to examples of the disclosure.

FIG. 10A illustrates an exemplary first scan step of a self-capacitancescan type on a touch screen according to examples of the disclosure.

FIG. 10B illustrates an exemplary second scan step of a self-capacitancescan type on a touch screen according to examples of the disclosure.

FIG. 10C illustrates exemplary commands transmitted by sense circuitryto switching circuits for implementing the first and second scan stepsof FIGS. 10A and 10B according to examples of the disclosure.

FIG. 10D illustrates an exemplary pen row scan type performed in asupernode of a touch screen according to examples of the disclosure.

FIG. 10E illustrates exemplary commands transmitted by sense circuitryto switching circuits for implementing pen scans according to examplesof the disclosure.

FIG. 10F illustrates exemplary switching circuit command combinationsthat can be utilized to implement the touch screen scans discussed withreference to FIGS. 6A-6D according to examples of the disclosure.

FIG. 11A illustrates an exemplary switching circuit configuration inwhich PMBs include switches that correspond to scan types and signalsaccording to examples of the disclosure.

FIG. 11B illustrates an exemplary logic structure for a PMB interfaceand PMB logic for implementing pen row and pen column scans on the touchscreen according to examples of the disclosure.

FIG. 11C illustrates exemplary states of switches in PMBs incorrespondence to various control signals received by a switchingcircuit from sense circuitry according to examples of the disclosure.

FIG. 12A illustrates an exemplary first scan step of a self-capacitancescan type performed in a region of a touch screen during a first timeperiod according to examples of the disclosure.

FIG. 12B illustrates an exemplary first scan step of a self-capacitancescan type performed in another region of the touch screen during asecond time period according to examples of the disclosure.

FIG. 12C illustrates exemplary shifting of switch control informationfrom one PMB to another PMB according to examples of the disclosure.

DETAILED DESCRIPTION

In the following description of examples, reference is made to theaccompanying drawings which form a part hereof, and in which it is shownby way of illustration specific examples that can be practiced. It is tobe understood that other examples can be used and structural changes canbe made without departing from the scope of the disclosed examples.

Some capacitive touch sensor panels can be formed by a matrix ofsubstantially transparent or non-transparent conductive plates made ofmaterials such as Indium Tin Oxide (ITO), and some touch screens can beformed by at least partially integrating touch sensing circuitry into adisplay pixel stackup (i.e., the stacked material layers forming thedisplay pixels). The conductive plates can be electrically connected tosense circuitry for sensing touch events on the touch screen. In someexamples, many different types of scans can be implemented on a touchscreen, and thus it can be beneficial for the architecture of the touchscreen to have sufficient flexibility to allow for implementation ofthese different types of scans on the touch screen. Further, in someexamples, a touch screen can include a relatively large number ofconductive plates on which touch events can be sensed. The examples ofthe disclosure provide various touch sensing architectures that arespace-efficient and flexible.

FIGS. 1A-1C show example systems in which a touch screen according toexamples of the disclosure may be implemented. FIG. 1A illustrates anexample mobile telephone 136 that includes a touch screen 124. FIG. 1Billustrates an example digital media player 140 that includes a touchscreen 126. FIG. 1C illustrates an example portable computing device 144that includes a touch screen 128. Touch screens 124, 126, and 128 can bebased on self-capacitance. A self-capacitance based touch system caninclude a matrix of small, individual plates of conductive material thatcan be referred to as touch node electrodes (as described below withreference to touch screen 220 in FIG. 2). For example, a touch screencan include a plurality of individual touch node electrodes, each touchnode electrode identifying or representing a unique location on thetouch screen at which touch or proximity (i.e., a touch or proximityevent) is to be sensed, and each touch node electrode being electricallyisolated from the other touch node electrodes in the touch screen/panel.Such a touch screen can be referred to as a pixelated touch screen onwhich the touch node electrodes can be used to perform various types ofscans, such as self-capacitance scans, mutual capacitance scans, etc.For example, during a self-capacitance scan, a touch node electrode canbe stimulated with an AC waveform, and the self-capacitance to ground ofthe touch node electrode can be measured. As an object approaches thetouch node electrode, the self-capacitance to ground of the touch nodeelectrode can change. This change in the self-capacitance of the touchnode electrode can be detected and measured by the touch sensing systemto determine the positions of multiple objects when they touch, or comein proximity to, the touch screen. In some examples, the electrodes of aself-capacitance based touch system can be formed from rows and columnsof conductive material, and changes in the self-capacitance to ground ofthe rows and columns can be detected, similar to above. In someexamples, a touch screen can be multi-touch, single touch, projectionscan, full-imaging multi-touch, capacitive touch, etc.

FIG. 2 is a block diagram of an example computing system 200 thatillustrates one implementation of an example touch screen 220 accordingto examples of the disclosure. Computing system 200 can be included in,for example, mobile telephone 136, digital media player 140, portablecomputing device 144, or any mobile or non-mobile computing device thatincludes a touch screen, including a wearable device. Computing system200 can include a touch sensing system including one or more touchprocessors 202, peripherals 204, a touch controller 206, and touchsensing circuitry (described in more detail below). Peripherals 204 caninclude, but are not limited to, random access memory (RAM) or othertypes of memory or storage, watchdog timers and the like. Touchcontroller 206 can include, but is not limited to, one or more sensechannels 208 and channel scan logic 210. Channel scan logic 210 canaccess RAM 212, autonomously read data from sense channels 208 andprovide control for the sense channels. In addition, channel scan logic210 can control sense channels 208 to generate stimulation signals atvarious frequencies and phases that can be selectively applied to thetouch nodes of touch screen 220, as described in more detail below. Insome examples, touch controller 206, touch processor 202 and peripherals204 can be integrated into a single application specific integratedcircuit (ASIC), and in some examples can be integrated with touch screen220 itself.

Touch screen 220 can include touch sensing circuitry that can include acapacitive sensing medium having a plurality of electrically isolatedtouch node electrodes 222 (e.g., a pixelated touch screen). Touch nodeelectrodes 222 can be coupled to sense channels 208 in touch controller206, can be driven by stimulation signals from the sense channelsthrough drive/sense interface 225, and can be sensed by the sensechannels through the drive/sense interface as well, as described above.Labeling the conductive plates used to detect touch (i.e., touch nodeelectrodes 222) as “touch node” electrodes can be particularly usefulwhen touch screen 220 is viewed as capturing an “image” of touch (a“touch image”). In other words, after touch controller 206 hasdetermined an amount of touch detected at each touch node electrode 222in touch screen 220, the pattern of touch node electrodes in the touchscreen at which a touch occurred can be thought of as a touch image(e.g., a pattern of fingers touching the touch screen).

Computing system 200 can also include a host processor 228 for receivingoutputs from touch processor 202 and performing actions based on theoutputs. For example, host processor 228 can be connected to programstorage 232 and a display controller, such as an LCD driver 234. The LCDdriver 234 can provide voltages on select (gate) lines to each pixeltransistor and can provide data signals along data lines to these sametransistors to control the pixel display image as described in moredetail below. Host processor 228 can use LCD driver 234 to generate adisplay image on touch screen 220, such as a display image of a userinterface (UI), and can use touch processor 202 and touch controller 206to detect a touch on or near touch screen 220. The touch input can beused by computer programs stored in program storage 232 to performactions that can include, but are not limited to, moving an object suchas a cursor or pointer, scrolling or panning, adjusting controlsettings, opening a file or document, viewing a menu, making aselection, executing instructions, operating a peripheral deviceconnected to the host device, answering a telephone call, placing atelephone call, terminating a telephone call, changing the volume oraudio settings, storing information related to telephone communicationssuch as addresses, frequently dialed numbers, received calls, missedcalls, logging onto a computer or a computer network, permittingauthorized individuals access to restricted areas of the computer orcomputer network, loading a user profile associated with a user'spreferred arrangement of the computer desktop, permitting access to webcontent, launching a particular program, encrypting or decoding amessage, and/or the like. Host processor 228 can also perform additionalfunctions that may not be related to touch processing.

Note that one or more of the functions described herein, including theconfiguration of switches, can be performed by firmware stored in memory(e.g., one of the peripherals 204 in FIG. 2) and executed by touchprocessor 202, or stored in program storage 232 and executed by hostprocessor 228. The firmware can also be stored and/or transported withinany non-transitory computer-readable storage medium for use by or inconnection with an instruction execution system, apparatus, or device,such as a computer-based system, processor-containing system, or othersystem that can fetch the instructions from the instruction executionsystem, apparatus, or device and execute the instructions. In thecontext of this document, a “non-transitory computer-readable storagemedium” can be any medium (excluding signals) that can contain or storethe program for use by or in connection with the instruction executionsystem, apparatus, or device. The computer-readable storage medium caninclude, but is not limited to, an electronic, magnetic, optical,electromagnetic, infrared, or semiconductor system, apparatus or device,a portable computer diskette (magnetic), a random access memory (RAM)(magnetic), a read-only memory (ROM) (magnetic), an erasableprogrammable read-only memory (EPROM) (magnetic), a portable opticaldisc such a CD, CD-R, CD-RW, DVD, DVD-R, or DVD-RW, or flash memory suchas compact flash cards, secured digital cards, USB memory devices,memory sticks, and the like.

The firmware can also be propagated within any transport medium for useby or in connection with an instruction execution system, apparatus, ordevice, such as a computer-based system, processor-containing system, orother system that can fetch the instructions from the instructionexecution system, apparatus, or device and execute the instructions. Inthe context of this document, a “transport medium” can be any mediumthat can communicate, propagate or transport the program for use by orin connection with the instruction execution system, apparatus, ordevice. The transport medium can include, but is not limited to, anelectronic, magnetic, optical, electromagnetic or infrared wired orwireless propagation medium.

FIG. 3A illustrates an exemplary touch sensor circuit 300 correspondingto a self-capacitance touch node electrode 302 and sensing circuit 314according to examples of the disclosure. Touch node electrode 302 cancorrespond to touch node electrode 222. Touch node electrode 302 canhave an inherent self-capacitance to ground associated with it, and alsoan additional self-capacitance to ground that is formed when an object,such as finger 305, is in proximity to or touching the electrode. Thetotal self-capacitance to ground of touch node electrode 302 can beillustrated as capacitance 304. Touch node electrode 302 can be coupledto sensing circuit 314. Sensing circuit 314 can include an operationalamplifier 308, feedback resistor 312, feedback capacitor 310 and aninput voltage source 306, although other configurations can be employed.For example, feedback resistor 312 can be replaced by a switchedcapacitor resistor to reduce a parasitic capacitance effect that can becaused by a variable feedback resistor. Touch node electrode 302 can becoupled to the inverting input of operational amplifier 308. An ACvoltage source 306 (Vac) can be coupled to the non-inverting input ofoperational amplifier 308. Touch sensor circuit 300 can be configured tosense changes in the total self-capacitance 304 of the touch nodeelectrode 302 induced by a finger or object either touching or inproximity to the touch sensor panel. The amplitude of the signal atoutput 320 can change as a function of a change in capacitance 304 dueto the presence of a proximity or touch event. Therefore the signal fromoutput 320 can be used by a processor or dedicated logic to determinethe presence of a proximity or touch event, in some examples, afteranalog-to-digital conversion and/or digital signal processing, which mayinclude, but is not limited to, demodulation and filtering. Additionalexemplary details of self-capacitance touch sensing, as described above,are described in U.S. patent application Ser. No. 14/067,870, publishedas U.S. Publication No. 2015/0035787, entitled “Self capacitance touchsensing,” the contents of which is hereby incorporated by reference forall purposes.

FIG. 3B illustrates an exemplary touch sensor circuit 330 correspondingto a mutual capacitance sensing circuit 331 according to examples of thedisclosure. Touch sensor circuit 330 can be utilized to sense the mutualcapacitance(s) between touch node electrodes (e.g., touch nodeelectrodes 222) on the touch screen of the disclosure. The structure oftouch sensor circuit 330 can be substantially that of touch sensorcircuit 300 in FIG. 3A, except that the non-inverting input ofoperational amplifier 308 can be coupled to reference voltage 322 (e.g.,a direct current (DC) reference voltage). Mutual capacitance sensingcircuit 331 can sense changes in mutual capacitance 324 between a touchnode electrode 302A that is driven (e.g., driven by AC voltage source306) and a touch node electrode 302B that is coupled to the invertinginput of operational amplifier 308 and sensed by touch sensor circuit330. The remaining details of touch sensor circuit 330 can be the sameas those of touch sensor circuit 300 in FIG. 3A, and will not berepeated here for brevity.

FIG. 3C illustrates an exemplary sensor circuit 360 corresponding to apen detection sensing circuit 361 according to examples of thedisclosure. Sensor circuit 360 can be utilized to sense the mutualcapacitance(s) between a pen or stylus 328 and a touch node electrode302 (e.g., touch node electrode 222) on the touch screen of thedisclosure. The structure of sensor circuit 360 can be substantiallythat of touch sensor circuit 330 in FIG. 3B, the details of which willnot be repeated here for brevity. In some examples, pen or stylus 328can be an active pen or stylus that actively modulates capacitance 326between an electrode in the pen or stylus 328 (e.g., by driving theelectrode in the pen with an AC voltage source 306) and a touch nodeelectrode 302 on the touch screen, which pen detection circuit 361 cansense.

Referring back to FIG. 2, in some examples, touch screen 220 can be anintegrated touch screen in which touch sensing circuit elements of thetouch sensing system can be integrated into the display pixel stackupsof a display. The circuit elements in touch screen 220 can include, forexample, elements that can exist in LCD or other displays, such as oneor more pixel transistors (e.g., thin film transistors (TFTs)), gatelines, data lines, pixel electrodes and common electrodes. In a givendisplay pixel, a voltage between a pixel electrode and a commonelectrode can control a luminance of the display pixel. The voltage onthe pixel electrode can be supplied by a data line through a pixeltransistor, which can be controlled by a gate line. It is noted thatcircuit elements are not limited to whole circuit components, such as awhole capacitor, a whole transistor, etc., but can include portions ofcircuitry, such as only one of the two plates of a parallel platecapacitor. FIG. 4 illustrates an example configuration in which commonelectrodes 402 can form portions of the touch sensing circuitry of atouch sensing system—in some examples of this disclosure, the commonelectrodes can form touch node electrodes used to detect a touch imageon touch screen 400, as described above. Each common electrode 402(which can define a “touch region” of the touch screen) can include aplurality of display pixels 401, and each display pixel 401 can includea portion of a common electrode 402, which can be a circuit element ofthe display system circuitry in the pixel stackup (i.e., the stackedmaterial layers forming the display pixels) of the display pixels ofsome types of LCD or other displays that can operate as part of thedisplay system to display a display image.

In the example shown in FIG. 4, each common electrode 402 can serve as amulti-function circuit element that can operate as display circuitry ofthe display system of touch screen 400 and can also operate as touchsensing circuitry of the touch sensing system. In this example, eachcommon electrode 402 can operate as a common electrode of the displaycircuitry of the touch screen 400, as described above, and can alsooperate as touch sensing circuitry of the touch screen. For example, acommon electrode 402 can operate as a capacitive part of a touch nodeelectrode of the touch sensing circuitry during the touch sensing phase.Other circuit elements of touch screen 400 can form part of the touchsensing circuitry by, for example, switching electrical connections,etc. More specifically, in some examples, during the touch sensingphase, a gate line can be connected to a power supply, such as a chargepump, that can apply a voltage to maintain TFTs in display pixelsincluded in a touch node electrode in an “off” state. Stimulationsignals can be applied to common electrode 402. Changes in the totalself-capacitance of common electrode 402 can be sensed through anoperational amplifier, as previously discussed. The change in the totalself-capacitance of common electrode 402 can depend on the proximity ofa touch object, such as finger 305, to the common electrode. In thisway, the measured change in total self-capacitance of common electrode402 can provide an indication of touch on or near the touch screen.

In general, each of the touch sensing circuit elements may be either amulti-function circuit element that can form part of the touch sensingcircuitry and can perform one or more other functions, such as formingpart of the display circuitry, or may be a single-function circuitelement that can operate as touch sensing circuitry only. Similarly,each of the display circuit elements may be either a multi-functioncircuit element that can operate as display circuitry and perform one ormore other functions, such as operating as touch sensing circuitry, ormay be a single-function circuit element that can operate as displaycircuitry only. Therefore, in some examples, some of the circuitelements in the display pixel stackups can be multi-function circuitelements and other circuit elements may be single-function circuitelements. In other examples, all of the circuit elements of the displaypixel stackups may be single-function circuit elements.

In addition, although examples herein may describe the display circuitryas operating during a display phase, and describe the touch sensingcircuitry as operating during a touch sensing phase, it should beunderstood that a display phase and a touch sensing phase may beoperated at the same time, e.g., partially or completely overlap, or thedisplay phase and touch sensing phase may operate at different times.Also, although examples herein describe certain circuit elements asbeing multi-function and other circuit elements as beingsingle-function, it should be understood that the circuit elements arenot limited to the particular functionality in other examples. In otherwords, a circuit element that is described in one example herein as asingle-function circuit element may be configured as a multi-functioncircuit element in other examples, and vice versa.

The common electrodes 402 (i.e., touch node electrodes) and displaypixels 401 of FIG. 4 are shown as rectangular or square regions on touchscreen 400. However, it is understood that the common electrodes 402 anddisplay pixels 401 are not limited to the shapes, orientations, andpositions shown, but can include any suitable configurations accordingto examples of the disclosure. Further, the examples of the disclosurewill be provided in the context of a touch screen, but it is understoodthat the examples of the disclosure can similarly be implemented in thecontext of a touch sensor panel.

As described above, the self-capacitance of each touch node electrode(sometimes, common electrode 402) in touch screen 400 can be sensed tocapture a touch image across touch screen 400. To allow for the sensingof the self-capacitance of individual common electrodes 402, it can benecessary to route one or more electrical connections (e.g., touch nodetraces) between each of the common electrodes and the touch sensingcircuitry (e.g., sense channels 208 or sensing circuit 314) of touchscreen 400.

FIG. 5A illustrates an exemplary touch node electrode 502 routingconfiguration in which touch node traces 504 can be routed directly fromtouch node electrodes 502 to sense circuitry 508 according to examplesof the disclosure. Similar to as discussed before, touch screen 500 caninclude touch node electrodes 502. Sense circuitry 508 can correspond tosense channels 208 and/or sensing circuits 314, for example. In theexample of FIG. 5A, each touch node electrode 502 can correspond to itsown sense channel in sense circuitry 508 (e.g., each touch nodeelectrode can be coupled, via a respective touch node trace 504, to itsown driving and/or sensing circuitry in the sense circuitry—e.g.,sensing circuit 314). In other words, sense circuitry 508 can includemultiple sense channels to which touch node electrodes 502 can becoupled, and by which the touch node electrodes can be sensed, asdescribed with reference to FIGS. 3A-3C. In the example illustrated,touch screen 500 can include 144 touch node electrodes 502 (12 touchnodes horizontally, and 12 touch nodes vertically), though it isunderstood that different numbers and configurations of touch nodeelectrodes can be utilized in accordance with the examples of thedisclosure.

Each of touch node electrodes 502 can be coupled to sense circuitry 508via respective touch node traces 504. Thus, in some examples, 12 touchnode traces 504 can be coupled to 12 respective touch node electrodes502 in a column of touch node electrodes on touch screen 500 (partiallyillustrated in FIG. 5A for ease of description). These 12 touch nodetraces 504 for each column of touch node electrodes 502 can be coupledto sense circuitry 508 for a total of 144 touch node traces coupledbetween touch screen 500 and sense circuitry 508. In some examples,touch screen 500 and portions of the 144 touch node traces 504 can bedisposed on a first substrate (e.g., a glass substrate), remainingportions of the 144 touch node traces can be disposed on a secondsubstrate (e.g., a connector connecting the touch screen and sensecircuitry 508, such as a flex connector), and the sense circuitry can bedisposed on a third substrate (e.g., an integrated circuit on a mainlogic board of a device of which the touch screen is a part). It isunderstood that in some examples, touch screen 500 (including touch nodeelectrodes 502), touch node traces 504 and sense circuitry 508 can bedisposed on the same substrate or on different substrates in a differentconfiguration than that described above, though the description thatfollows will assume that the touch screen, at least a portion of thetouch node traces and the sense circuitry are disposed on differentsubstrates.

In some examples, especially in situations where touch screen 500includes a relatively large number of touch node electrodes 502 (e.g.,40×32 touch node electrodes=1280 touch node electrodes, or 48×36 touchnode electrodes=1728 touch node electrodes), it can be difficult toroute the resulting relatively large number of touch node traces 504between touch screen 500 and sense circuitry 508. For example, it can bedifficult to include 1280 or 1728 touch node traces 504 on a flexconnector that can be coupled between touch screen 500 and sensecircuitry 508. Sensing touch on only portions of touch screen 500 at atime, or configuring touch node electrodes 502 to share sense channels(e.g., sensing circuits 314) on sense circuitry 508, can reduce thenumber of touch node traces 504 needed to couple the touch screen to thesense circuitry. Additionally, such sensing and sharing schemes canreduce the quantity of driving and/or sensing circuitry required insense circuitry 508 for proper touch screen operation. The examples thatfollow will illustrate the above-mentioned advantages.

FIG. 5B illustrates an exemplary touch node electrode 502 routingconfiguration that includes switching circuits 506 a, 506 b and 506 c(referred to collectively as 506) according to examples of thedisclosure. In touch screen 500 of FIG. 5B, only a portion of touch nodeelectrodes 502 can be driven, sensed, etc., at a given moment in time,as will be described in more detail below. As a result, the number ofseparate touch node electrode traces 504 that may need to be coupled tosense circuitry 508 can be less than the total number of touch nodeelectrodes 502 included in touch screen 500. Specifically, touch nodetraces 504 can be individually coupled to touch node electrodes 502, asdescribed with reference to FIG. 5A. However, instead of being routeddirectly to sense circuitry 508, touch node traces 504 can be routedfrom respective touch node electrodes 502 to switching circuits 506. Inthe example of FIG. 5B, three switching circuits 506 are illustrated,but it is understood that the examples of the disclosure can similarlybe implemented in configurations employing different numbers ofswitching circuits (e.g., a single switching circuit).

Traces 510 a, 510 b and 510 c (referred to collectively as 510) cancouple switching circuits 506 to sense circuitry 508. Specifically,respective traces 510 can be coupled to respective sense channels insense circuitry 508 (e.g., respective sensing circuits 314 in the sensecircuitry). Traces 510 can be shared by multiple touch node electrodes502, as will be described below, and thus can be referred to as sharedtraces. Similar to FIG. 5A, touch screen 500 (including touch nodeelectrodes 502) and switching circuits 506 can be disposed on a firstsubstrate (e.g., a glass substrate), shared traces 510 can be disposedon a second substrate (e.g., a connector coupling the touch screen andsense circuitry 508, such as a flex connector), and the sense circuitrycan be disposed on a third substrate (e.g., an integrated circuit on amain logic board of a device of which the touch screen is a part). It isunderstood that in some examples, touch screen 500 (including touch nodeelectrodes 502), switching circuits 506, touch node traces 504, sharedtraces 510 and sense circuitry 508 can be disposed on the same substrateor on different substrates in a different configuration than thatdescribed above.

The operation of the touch node electrode 502 routing configuration ofFIG. 5B will now be described. Switching circuits 506 can have theability to selectively couple one or more of shared traces 510 to one ormore touch node electrodes 502 to which the switching circuits arecoupled via respective ones of touch node traces 504. Because respectivetraces 510 can, in turn, be coupled to respective sense channels insense circuitry 508, as described above, switching circuits 506 can,thus, selectively couple a given sense channel in sense circuitry 508(e.g., sensing circuit 314) to a given touch node electrode 502 viashared traces 510 and touch node traces 504. This ability to assign agiven sense channel in sense circuitry 508 to a first touch nodeelectrode 502 during a first time period, and to a second touch nodeelectrode during a second time period, can allow for a single sensechannel to be used for sensing touch on multiple touch node electrodesat different times, and can thus reduce the quantity of such sensechannels (e.g., sensing circuits 314) needed in the sense circuitry forproper touch screen operation. Relatedly, the number of shared traces510 can be less than the number of touch node traces 504. For example,focusing on switching circuit 506 a in FIG. 5B, 48 touch node traces 504can couple switching circuit 506 a to the 48 touch node electrodes 502in region 512 of touch screen 500, as described previously. The numberof shared traces 510 a coupling switching circuit 506 a and sensecircuitry 508 can depend on how many of touch node electrodes 502 inregion 512 of touch screen 500 need to be independently driven and/orsensed at a given moment in time. For example, if one-fourth of thetouch node electrodes 502 in region 512 of touch screen 500 need to beindependently driven and/or sensed at a given moment in time, then only12 shared traces 510 a need to couple switching circuit 506 a to sensecircuitry 508—during a first time period, switching circuit 506 a cancouple those 12 shared traces to 12 touch node electrodes, during asecond time period, the switching circuitry can couple those 12 sharedtraces to 12 different touch node electrodes, and so on. The specificratio of the number of shared traces 510 to the number of touch nodetraces 504 can depend on the particular operating schemes (e.g., touchscreen scan configurations) of touch screen 500. However, in accordancewith the particular example disclosed above, the number of tracesdisposed on the flex connector (e.g., shared traces 510) in FIG. 5B canbe less than the number of traces disposed on the flex connector (e.g.,traces 504) in FIG. 5A. This reduction of traces can similarly beimplemented in touch screens having different operating requirementsthan those discussed above.

FIGS. 6A-6D illustrate exemplary touch screen scan configurationsaccording to examples of the disclosure. The following touch screen scanconfigurations are provided by way of example only; other touch screenscan configurations can be implemented according to examples of thedisclosure. FIG. 6A illustrates exemplary display 602, touch 604 and penframes 606 according to examples of the disclosure. Display frame 602can include two touch frames 604, which can, in turn, include two penframes 606. In some examples, display frame 602 and touch frame 604 canoccur at the same time and have the same length (i.e., display frame 602can include one touch frame 604). The length of display frame 602 can berelated to the frequency with which a display image displayed on thetouch screen of the disclosure is updated, the length of touch frame 604can be related to the frequency with which touch is sensed across theentire touch screen of the disclosure, and the length of pen frame 606can be related to the frequency with which the location of a pen orstylus is detected on the touch screen of the disclosure.

Touch frame 604 can include time periods during which various pen, touchor display operations can be performed. The discussion that follows willfocus on touch frame 604, but as is apparent from FIG. 6A, the structureof display frame 602 can be based on the structure of touch frame 604,and the structure of the touch frame can be based on the structure ofpen frame 606. Touch frame 604 can include two time periods 624 duringwhich various pen detection and mutual capacitance scans can beperformed on the touch screen of the disclosure, as will be described inmore detail later. Touch frame 604 can also include four time periods608, 612, 616 and 620 during which touch can be sensed in differentregions of the touch screen of the disclosure. For example, during timeperiod 608, region 610 of the touch screen can be scanned in aself-capacitance configuration (as described with reference to FIG. 3A,for example) to sense touch in region 610 of the touch screen.Similarly, during time period 612, region 614 of the touch screen can bescanned in a self-capacitance configuration to sense touch in region 614of the touch screen. Time periods 616 and 620 can similarly correspondto the sensing of touch in regions 618 and 622 of the touch screen,respectively. In this way, touch can be sensed across the entirety ofthe touch screen by the time touch frame 604 ends. In some examples, adisplay image displayed by the touch screen can be updated during timeperiods between time periods 608, 612, 616, 620 and 624 of touch frame604.

FIG. 6B illustrates exemplary details of time period 624 in touch frame604 according to examples of the disclosure. As described above, duringtime period 624, various pen-related and mutual capacitance scans can beperformed on the touch screen of the disclosure. Specifically, timeperiod 624 can include four scan periods: pen detect scan 628, mutualcapacitance scan 634, pen column scan 632 and pen row scan 630. Asstated previously, these scan periods are provided by way of exampleonly, and it is understood that time period 624 can include alternativescan periods to those illustrated.

During pen detect 628 scan period, 4×4 blocks of touch node electrodescan be scanned in a mutual capacitance configuration (as described withreference to FIG. 3A, for example) to determine an approximate locationof a pen or stylus on or in proximity to the touch screen. In someexamples, these 4×4 blocks of touch node electrodes can be referred toas “supernodes.” A 4×4 configuration of a supernode is given by exampleonly, and it is understood that supernodes may have configurationsdifferent than a 4×4 configuration (e.g., a 2×2 configuration, a 3×3configuration, etc.). All of the touch node electrodes in a givensupernode can be coupled to common sense circuitry (e.g., sense circuit361 in FIG. 3C), and thus can act as a single large touch node electrodewhen detecting mutual capacitance modulations that may result from a penor stylus being in proximity to the given supernode. In some examples,all of the supernodes on the touch screen can be scanned atsubstantially the same time so that pen detection can occur in a singlescan period, as illustrated in scan configuration 638. Specifically, alltouch node electrodes labeled “S1” can be coupled to a first sensechannel (e.g., sense circuit 361 in FIG. 3C), all touch node electrodeslabeled “S2” can be coupled to a second sense channel, and so on, asillustrated. In the illustrated example, nine 4×4 supernodes can becoupled to nine different sense channels—channels 1 through 9. In someexamples, pen detection can occur during two or more scan periods.During a first pen detect scan period, the first halves of all of thesupernodes on the touch screen can be scanned in a mutual capacitanceconfiguration (e.g., as described with reference to FIG. 3C) to detectthe presence of a pen or stylus in proximity to those halves. During asecond pen detect scan period, the remaining halves of all of thesupernodes on the touch screen can be scanned in the mutual capacitanceconfiguration (e.g., as described with reference to FIG. 3C) to detectthe presence of a pen or stylus in proximity to those remaining halves.As a result, the presence or absence of a pen or stylus can have beendetected across the entirety of the touch screen at the completion ofthe first and second pen detect scan periods. In some examples, notevery touch node electrode in a supernode needs to be scanned during thepen detection scan period(s), because the pen detection scan period(s)may only need to approximately determine to which supernode the pen orstylus is in proximity. For example, in some examples, touch nodeelectrodes in a supernode can be scanned (e.g., as described withreference to FIG. 3C) in a checkerboard pattern so that every othertouch node electrode is coupled to a sense channel and scanned in amutual capacitance configuration. Reducing the number of touch nodeelectrodes that are coupled to sense circuitry, such as sense channels,can reduce the capacitive load on that sense circuitry, and can yieldbenefits such as reduced noise gain and improved signal bandwidth,resulting in improved signal-to-noise ratio.

In some examples, pen row 630 and pen column 632 scan periods can beperformed in response to detecting a pen or stylus in proximity to thetouch screen during the pen detect 628 scan period. In some examples,when a pen or stylus is detected in proximity to a given supernode, thetouch node electrodes in that supernode and all surrounding supernodes(e.g., the given supernode and the eight supernodes surrounding thegiven supernode) can be scanned in a pen row 640 and a pen column 642configuration. If the given supernode is at an edge or corner of thetouch screen, then the given supernode may have fewer than eightsurrounding supernodes—in such circumstances, those supernodes can bescanned in the pen row 640 and pen column 642 configurations. In the penrow configuration 640, touch node electrodes in a row of touch nodeelectrodes of each supernode to be scanned can be scanned in a mutualcapacitance configuration (e.g., as described with respect to FIG. 3C),and all of the touch node electrodes in that row can be sensed by thesame sense channel (e.g., sense circuit 361 in FIG. 3C). For example,the top row of touch node electrodes in the upper-left-most supernode tobe scanned can be coupled to sense channel “S1”, as illustrated, andsensed in the mutual capacitance configuration. The remaining rows oftouch node electrodes in the supernodes to be scanned can similarly becoupled to respective sense channels and sensed in mutual capacitanceconfigurations, as illustrated. In the example illustrated in FIG. 6B,36 supernode “row segments” (e.g., 1×4 collections of touch nodeelectrodes) can be coupled to 36 different respective sensechannels—channels 1 through 36.

In addition to the pen row scan period 630, a pen column scan period 632can be performed. Analogously to the pen row scan configuration 640, inthe pen column scan configuration 642, touch node electrodes in a columnof touch node electrodes of each supernode to be scanned can be scannedin a mutual capacitance configuration (e.g., as described with referenceto FIG. 3C), and all of the touch node electrodes in that column can besensed by the same sense channel (e.g., sense circuit 361 in FIG. 3C).For example, the left column of touch node electrodes in theupper-left-most supernode to be scanned can be coupled to sense channel“S1”, as illustrated, and sensed in the mutual capacitance configuration(e.g., as described with reference to FIG. 3C). The remaining columns oftouch node electrodes in the supernodes to be scanned can similarly becoupled to respective sense channels and sensed in mutual capacitanceconfigurations (e.g., as described with reference to FIG. 3C), asillustrated. In the example illustrated in FIG. 6B, 36 supernode “columnsegments” (e.g., 4×1 collections of touch node electrodes) can becoupled to 36 different respective sense channels—channels 1 through 36.

In some examples, time period 624 can also include a mutual capacitancescan time period 634. During the mutual capacitance scan time period634, the entire touch screen can be scanned as illustrated in mutualcapacitance scan configuration 644. Specifically, every 2×2 collectionof touch node electrodes can have the following configuration: thetop-left touch node electrode can be sensed (e.g., coupled to a sensechannel, such as sense circuit 331 in FIG. 3B, and referred to as a “Stouch node electrode”), the bottom-right touch node electrode can bedriven (e.g., coupled to a drive voltage source, such as voltage source306 in FIG. 3B, and referred to as a “D touch node electrode”), and thetop-right and bottom-left touch node electrodes can be biased at a biasvoltage (e.g., coupled to a bias voltage source, and referred to as a“VB touch node electrode”). The above-described configuration of touchnode electrodes can allow for measurement of a mutual capacitance (andchanges in the mutual capacitance) between the D and S touch nodeelectrodes. In some examples, these mutual capacitance measurements canbe obtained by stimulating one or more D touch node electrodes on thetouch screen with one or more stimulation buffers, biasing one or moreVB touch node electrodes with one or more bias buffers (e.g., one ormore AC ground buffers), and/or sensing one or more S touch nodeelectrodes with one or more sense amplifiers (e.g., sense circuitry).The above-described mutual capacitance configuration 644 is exemplaryonly, and it is understood that other mutual capacitance configurationsare similarly within the scope of the disclosure (e.g., a configurationin which at least one touch node electrode is driven and at least onetouch node electrode is sensed).

FIG. 6C illustrates exemplary details of time periods 608, 612, 616 and620 in touch frame 604 according to examples of the disclosure. Asdescribed above, during time periods 608, 612, 616 and 620, variousself-capacitance scans can be performed on the touch screen of thedisclosure. The details of time periods 608, 612, 616 and 620 can besubstantially the same, except that the scans described below can beperformed in different regions of the touch screen, as described withreference to FIG. 6A. Therefore, the following discussion will focus ontime period 608, though it is understood that the discussion can applysimilarly to time periods 612, 616 and 620.

Time period 608 can include four scan periods: self-capacitance scanstep 1 650, self-capacitance scan step 2 652, self-capacitance scan step3 654 and self-capacitance scan step 4 656. As stated previously, thesescan periods are provided by way of example only, and it is understoodthat time period 608 can include alternative scan periods to thoseillustrated.

During self-capacitance scan step 1 650, touch node electrodes in aparticular region of the touch screen (e.g., region 610, 614, 618 and/or622 in FIG. 6A) can be scanned as illustrated in configuration 658.Specifically, in every 2×2 collection of touch node electrodes in theregion to be scanned, the top-left touch node electrode can be drivenand sensed (e.g., to sense a self-capacitance of that touch nodeelectrode, as described with reference to FIG. 3A), the bottom-righttouch node electrode can be biased at a bias voltage, and the top-rightand bottom-left touch node electrodes can be driven but not sensed.Thus, in FIG. 6C, the DS touch node electrode can be coupled to sensecircuitry (e.g., sense circuitry 314 in FIG. 3A), the D touch nodeelectrodes can be coupled to one or more stimulation buffers, and the VBtouch node electrode can be coupled to a bias buffer (e.g., an AC groundbuffer). In some examples, the sense circuitry to which the DS touchnode electrode is coupled can share the same stimulation source (e.g.,AC voltage source 306) as the stimulation buffer(s) to which the D touchnode electrodes are coupled, because the DS and D touch node electrodescan be driven by the same stimulation signal.

Self-capacitance scan step 2 652, self-capacitance scan step 3 654 andself-capacitance scan step 4 656 can drive and sense, drive but notsense, and bias different permutations of touch node electrodes, asillustrated in configurations 660, 662 and 664, such that at the end ofself-capacitance scan step 4, each of the touch node electrodes in thegroup of four touch node electrodes has been driven and sensed at somepoint in time. The order of scan steps provided is exemplary only, andit is understood that a different order of scan steps could be utilized.By performing such self-capacitance measurements across part or all ofthe touch screen of the disclosure, a self-capacitance touch image onthe touch screen can be captured.

As described above, in some examples, the self-capacitance scansdiscussed above can be performed in a region by region manner on thetouch screen of the disclosure. For example, the self-capacitance scanscan first be performed in region 610 of touch screen 600, then in region614 of the touch screen, then in region 618 of the touch screen, andfinally in region 622 of the touch screen. While a given region of thetouch screen is being scanned in a self-capacitance configuration, theremaining regions of the touch screen can be configured in a way thatmirrors the self-capacitance scan taking place in the given region, aswill be described below.

FIG. 6D illustrates an exemplary configuration 666 of touch nodeelectrodes in regions 614, 618 and 622 of touch screen 600 while region610 is being scanned in a self-capacitance configuration as describedwith reference to FIG. 6C. Specifically, touch node electrodes in a 2×2group of touch node electrodes can be configured as illustrated inconfiguration 666, where three of the touch node electrodes can bedriven but not sensed, and the remaining one touch node electrode can bebiased at a bias voltage. The position of the touch node electrode thatis biased at the bias voltage (i.e., the VB touch node electrode) cancorrespond to the position of the VB touch node electrode inconfigurations 658, 660, 662 and 664 in FIG. 6C. That is to say thatwhen region 610 is being scanned according to configuration 658, the VBtouch node electrode in regions 614, 618 and 622 can be the lower-righttouch node electrode in a 2×2 group of touch node electrodes, asillustrated in configuration 666. Similarly, when region 610 is beingscanned according to configuration 660, the VB touch node electrode inregions 614, 618 and 622 can be the lower-left touch node electrode inthe 2×2 group of touch node electrodes, when region 610 is being scannedaccording to configuration 662, the VB touch node electrode in regions614, 618 and 622 can be the upper-left touch node electrode in the 2×2group of touch node electrodes, and when region 610 is being scannedaccording to configuration 664, the VB touch node electrode in regions614, 618 and 622 can be the upper-right touch node electrode in the 2×2group of touch node electrodes. The above-described touch node electrodeconfigurations can similarly apply to other regions of touch screen 600when regions other than region 610 are being scanned in aself-capacitance configuration.

As discussed above, in some examples, groups of touch node electrodes(“supernodes”) can be collectively scanned during certain time periodsin the operation of the touch screen of the disclosure. For example, allof the supernodes on the touch screen can be scanned concurrently duringa pen detection scan period, as described above with reference to FIG.6B. Thus, to be able to scan all of such supernodes on the touch screenconcurrently, there can be a minimum number of shared traces (e.g.,shared traces 510 in FIG. 5B) that can be required to couple switchingcircuits (e.g., switching circuits 506 in FIG. 5B) to sense circuitry(e.g., sense circuitry 508 in FIG. 5B). Further, the switching circuitsutilized by the touch screen may not align with the number and layout ofsupernodes on the touch screen—specifically, some supernodes on thetouch screen may extend across separate switching circuits, as will bedescribed below. In such configurations, shared traces can be sharedamongst multiple switching circuits.

FIGS. 7A-7C illustrate exemplary touch screen and switching circuitconfigurations according to examples of the disclosure. FIG. 7Aillustrates an exemplary touch screen 700 configuration in whichswitching circuits 706A, 706B, 706C and 706D (referred to collectivelyas 706) can correspond to full supercolumns 714 of supernodes 703 on thetouch screen. In the example of FIG. 7A, supernodes 703 can be made upof groups of 4×4 touch node electrodes 702, as illustrated. It isunderstood that other supernode configurations can similarly beimplemented according to the examples of the disclosure, though thediscussion that follows will be directed to 4×4 supernode configurationsfor ease of description.

Touch screen 700 can include 16 supernodes 703: four supernodeshorizontally by four supernodes vertically. Further, touch screen 700can include four switching circuits 706. Switching circuit 706 a can becoupled to the left-most four columns of touch node electrodes 702(i.e., the left-most supernode 703 supercolumn 714) via respective touchnode traces 704, switching circuit 706 b can be coupled to thecenter-left four columns of touch node electrodes via respective touchnode traces, switching circuit 706 c can be coupled to the center-rightfour columns of touch node electrodes via respective touch node traces,and switching circuit 706 d can be coupled to the right-most fourcolumns of touch node electrodes via respective touch node traces.

Focusing, for now, on exemplary self-capacitance scans to be performedon touch screen 700 (e.g., as discussed with reference to FIGS. 6C-6D),a complete self-capacitance scan of the touch screen can require 16 scansteps (e.g., scan steps 650, 652, 654 and 656 in FIG. 6C, repeated fourtimes across the touch screen as illustrated in FIG. 6D). Further, touchscreen 700, as illustrated, can include 256 touch node electrodes 702.As such, the number of unique sense channels required to perform theself-capacitance scan of touch screen 700 can be 16-256 touch nodeelectrodes divided by 16 scan steps. These 16 sense channels can becoupled to appropriate touch node electrodes 702 on touch screen 700 viaswitching circuits 706, each of which can be coupled to four sensechannels in sense circuitry 708 via respective traces 710A, 710B, 710Cand 710D (referred to collectively as 710). Therefore, each switchingcircuit 706 can correspond to one dedicated supercolumn 714, asillustrated.

In some examples, some supernodes on the touch screen can extend acrossmultiple switching circuits—FIG. 7B illustrates such a scenarioaccording to examples of the disclosure. Touch screen 730 in FIG. 7B caninclude 20, 4×4 supernodes 703: five supernodes horizontally, and foursupernodes vertically. Touch node electrodes 702 making up supernodes703 are only illustrated in the upper-left-most supernode of touchscreen 730 for simplicity of illustration, though it is understood thatthe remaining supernodes can similarly include touch node electrodes.

Touch screen 730 can include four switching circuits 706. Because touchscreen 730 can include five supercolumns 714 of supernodes 703, each ofswitching circuits 706 can be coupled to touch node electrodes 702 insupernodes in two supercolumns, as will be described below. Eachswitching circuit 706 can be coupled to five columns of touch nodeelectrodes 702. Specifically, switching circuit 706 a can be coupled toall of touch node electrodes 702 in supernodes 703 in supercolumn 714 a,as well as the left-most column of touch node electrodes in thesupernodes in supercolumn 714 b. Switching circuit 706 b can be coupledto the remaining touch node electrodes 702 in supercolumn 714 b, as wellas the left-two columns of touch node electrodes in supercolumn 714 c.Switching circuit 706 c can be coupled to the right-two columns of touchnode electrodes 702 in supercolumn 714 c, as well as the left-threecolumns of touch node electrodes in supercolumn 714 d. Finally,switching circuit 706 d can be coupled to the remaining column of touchnode electrodes 702 in supercolumn 714 d, as well as all of the touchnode electrodes in supercolumn 714 e.

Focusing, for now, on exemplary self-capacitance scans to be performedon touch screen 730 (e.g., as discussed with reference to FIGS. 6C-6D),a complete self-capacitance scan of the touch screen can require 16 scansteps (e.g., scan steps 650, 652, 654 and 656 in FIG. 6C, repeated fourtimes across the touch screen as illustrated in FIG. 6D). Further, touchscreen 730, as illustrated, can include 320 touch node electrodes 702.As such, the number of unique sense channels required to perform theself-capacitance scan of touch screen 730 can be 20-320 touch nodeelectrodes divided by 16 scan steps. These 20 sense channels can becoupled to appropriate touch node electrodes 702 on touch screen 730 viaswitching circuits 706. Because each switching circuit 706 may need tosupport a full and a partial, or two partial, columns 714 of supernodes703, as described above, neighboring switching circuits can share someconnections to sense channels in sense circuitry 708, so that thoseswitching circuits can each have access to the sense channels needed tocouple to the supernodes shared between those switching circuits. Inother words, in order for touch node electrodes 702 that are part of thesame supernode 703, but are coupled to different switching circuits 706,to be coupled to the same sense channel in sense circuitry 708, it canbe necessary for those different switching circuits to at leastpartially share a connection to the sense circuitry. For example,switching circuit 706 a and switching circuit 706 b can be partiallycoupled to sense circuitry 708 via shared traces 710 b—switching circuit706 a can have four dedicated connections to sense channels in sensecircuitry 708 via traces 710 a, and can share four connections to sensechannels in the sense circuitry with switching circuit 706 b via traces710 b. In this way, touch node electrodes 702 coupled to switchingcircuit 706 a and touch node electrodes coupled to switching circuit 706b that are part of the same supernode 703 can be coupled to the sameshared trace 710 b, and thus to the same sense channel in sensecircuitry 708. Switching circuit 706 b, switching circuit 706 c andswitching circuit 706 d can similarly share shared traces (e.g., traces710 c and 710 d) for the same reasons as described above.

FIG. 7C illustrates an exemplary touch screen having four rows ofsupernodes 703, and nine supercolumns 714 of supernodes according toexamples of the disclosure. Specifically, touch screen 760 in FIG. 7Ccan include 36, 4×4 supernodes 703: nine supernodes horizontally, andfour supernodes vertically. Touch node electrodes 702 making upsupernodes 703 are only illustrated in the upper-left-most supernode oftouch screen 760 for simplicity of illustration, though it is understoodthat the remaining supernodes can similarly include touch nodeelectrodes.

Touch screen 760, like touch screen 730 in FIG. 7B, can include fourswitching circuits 706, though each switching circuit in touch screen760 can support a greater number of traces 710 and touch node traces704. Because touch screen 760 can include nine supercolumns 714 ofsupernodes 703, each of switching circuits 706 can be coupled to touchnode electrodes 702 in supernodes in three supercolumns. In particular,each switching circuit 706 can be coupled to nine columns of touch nodeelectrodes 702. Specifically, switching circuit 706 a can be coupled toall of touch node electrodes 702 in supernodes 703 in supercolumns 714 aand 714 b, as well as the left-most column of touch node electrodes inthe supernodes in supercolumn 714 c. Switching circuit 706 b can becoupled to the remaining touch node electrodes 702 in supercolumn 714 c,all of the touch node electrodes in supercolumn 714 d, as well as theleft-two columns of touch node electrodes in supercolumn 714 e.Switching circuit 706 c can be coupled to the right-two columns of touchnode electrodes 702 in supercolumn 714 e, all of the touch nodeelectrodes in supercolumn 714 f, as well as the left-three columns oftouch node electrodes in supercolumn 714 g. Finally, switching circuit706 d can be coupled to the remaining column of touch node electrodes702 in supercolumn 714 g, as well as all of the touch node electrodes insupercolumns 714 h and 714 i.

Similar to as described with reference to FIG. 7B, each switchingcircuit 706 in FIG. 7C may need to support full and partial columns ofsupernodes 703, as described above. As such, neighboring switchingcircuits 706 can share some connections 710 to sense channels in sensecircuitry 708, so that those switching circuits can each have access tothe sense channels needed to couple to the supernodes 703 shared betweenthose switching circuits. For example, switching circuit 706 a andswitching circuit 706 b can be partially coupled to sense circuitry 708via shared traces 710 b—switching circuit 706 a can have eight dedicatedconnections to sense channels in sense circuitry 708 via traces 710 a,and can share four connections to sense channels in the sense circuitrywith switching circuit 706 b via traces 710 b. In this way, touch nodeelectrodes 702 coupled to switching circuit 706 a and touch nodeelectrodes coupled to switching circuit 706 b that are part of the samesupernode 703 can be coupled to the same shared trace 710 b, and thus tothe same sense channel in sense circuitry 708. Switching circuit 706 b,switching circuit 706 c and switching circuit 706 d can similarly shareshared traces (e.g., traces 710 d and 710 f) for the same reasons asdescribed above.

FIGS. 8A-8D illustrate exemplary interconnect structures for theswitching circuits of the touch screen according to examples of thedisclosure. FIG. 8A illustrates an exemplary switching circuit 806A,806B, 806C and 806D (referred to collectively as 806) configurationaccording to examples of the disclosure. The configuration of FIG. 8Acan be substantially that of FIG. 7A. Specifically, switching circuit806 a can be coupled to touch node electrodes 802 in supercolumn 814 aof supernodes, switching circuit 806 b can be coupled to touch nodeelectrodes in supercolumn 814 b of supernodes, switching circuit 806 ccan be coupled to touch node electrodes in supercolumn 814 c ofsupernodes, and switching circuit 806 d can be coupled to touch nodeelectrodes in supercolumn 814 d of supernodes, as previously describedwith reference to FIG. 7A. Respective switching circuits 806 can becoupled to touch node electrodes 802 in respective supercolumns 814 via64 traces 804A, 804B, 804C and 804D (referred to collectively as 804),because each supercolumn of supernodes can include 64 touch nodeelectrodes. Further, respective switching circuits 806 can be coupled torespective sense channels in sense circuitry 808 via four sense traces810A, 810B, 810C and 810D (referred to collectively as 810), aspreviously discussed.

Switching circuits 806 can include interconnect lines 820A, 820B, 820Cand 820D (referred to collectively as 820) that can facilitate thecoupling of touch node traces 804 to respective ones of sense traces810. Focusing on switching circuit 806 a (switching circuits 806 b, 806c and 806 d can be similarly structured), the switching circuit caninclude interconnect lines 820 a. Interconnect lines 820 a can becoupled to respective ones of sense traces 810 a, such that each sensetrace 810 a can be coupled to a different interconnect line 820 a. Touchnode traces 804 a can then be selectively coupled to respective ones ofinterconnect lines 820 a so as to couple touch node electrodes 802 toappropriate sense traces 810 a (and thus to appropriate sense channelsin sense circuitry 808) according to desired touch screen operation(e.g., according to any touch screen scan configuration, such asdescribed with reference to FIGS. 6A-6D).

In some examples, interconnect lines 820 a can extend acrosssubstantially the entire width of switching circuit 806 a. Further,although illustrated as single lines, it is understood that interconnectlines 820 a can each be comprised of multiple lines—specifically, asufficient number of lines so as to allow for implementation of desiredtouch screen scan configurations. For example, the total number of linesin interconnect lines 820 a can correspond to the maximum number ofsense channels in sense circuitry 808 to which touch node electrodes 802in column 814 a of touch node electrodes will be coupled at a givenmoment in time. For example, with respect to the self-capacitance scandescribed with reference to FIGS. 6C-6D and FIG. 7A, the maximum numberof sense channels in sense circuitry 808 to which touch node electrodes802 in column 814 a of touch node electrodes will be coupled at a givenmoment in time can be four, as previously described. Therefore,interconnect lines 820 a (and thus sense traces 810 a) can be comprisedof four lines that extend across substantially the entire width ofswitching circuit 806 a. The preceding discussion can apply analogouslyto switching circuits 806 b, 806 c and 806 d.

In some examples, neighboring switching circuits may need to shareconnections to sense circuitry, as described above with reference toFIGS. 7B-7C. FIG. 8B illustrates an exemplary switching circuit 806configuration in which neighboring switching circuits can shareconnections to sense circuitry 808 according to examples of thedisclosure. The configuration of FIG. 8B can be substantially that ofFIG. 7B. Specifically, switching circuit 806 a can be coupled to touchnode electrodes 802 in supercolumn 814 a and part of supercolumn 814 bof supernodes, switching circuit 806 b can be coupled to touch nodeelectrodes in part of supercolumn 814 b and part of supercolumn 814 c ofsupernodes, switching circuit 806 c can be coupled to touch nodeelectrodes in part of supercolumn 814 c and part of supercolumn 814 d ofsupernodes, and switching circuit 806 d can be coupled to touch nodeelectrodes in part of supercolumn 814 d and supercolumn 814 e ofsupernodes, as previously described with reference to FIG. 7B.Respective switching circuits 806 can be coupled to touch nodeelectrodes 802 via 80 traces 804, as described above with reference toFIG. 7B. Further, respective switching circuits 806 can be coupled torespective sense channels in sense circuitry 808 via sense traces 810.In some examples, switching circuits 806 can share sense traces 810. Forexample, switching circuit 806 a can be coupled to four sense channelsin sense circuitry 808 via four dedicated sense traces 810 a, and canalso be coupled to another four sense channels in the sense circuitryvia four shared traces 810 b that can be shared with switching circuit806 b. Switching circuit 806 b can be coupled to four sense channels insense circuitry 808 via shared traces 810 b, and can also be coupled toanother four sense channels in the sense circuitry via four sharedtraces 810 c that can be shared with switching circuit 806 c. Switchingcircuits 806 c and 806 d can be coupled to sense channels in sensecircuitry 808 in manners analogous to those described with reference toswitching circuits 806 a and 806 b, above.

Switching circuits 806 can include interconnect lines 820 and 822 a, 822b, 822 c and 822 d (referred to collectively as 822) that can facilitatethe coupling of touch node traces 804 to respective ones of traces 810.Focusing on switching circuit 806 a (switching circuits 806 b, 806 c and806 d can be similarly structured), the switching circuit can includeinterconnect lines 820 a and 822 a. Interconnect lines 820 a can becoupled to respective ones of traces 810 a, while interconnect lines 822a can be coupled to respective ones of shared traces 810 b that can beshared with switching circuit 806 b and further coupled to interconnectlines 820 b in switching circuit 806 b. Touch node traces 804 a can thenbe selectively coupled to respective ones of interconnect lines 820 aand 822 a so as to couple touch node electrodes 802 with appropriatetraces 810 a and 810 b (and thus with appropriate sense channels insense circuitry 808) according to desired touch screen operation (e.g.,according to any touch screen scan configuration, such as described withreference to FIGS. 6A-6D).

In some examples, interconnect lines 820 a and 822 a can extend acrosssubstantially the entire width of switching circuit 806 a. Further,although illustrated as single lines, it is understood that interconnectlines 820 a and 822 a can each be comprised of multiplelines—specifically, a sufficient number of lines so as to allow forimplementation of desired touch screen scan configurations. For example,the total number of lines in interconnect lines 820 a and 822 a cancorrespond to the maximum number of sense channels in sense circuitry808 to which the touch node electrodes 802 to which switching circuit806 a is coupled will be coupled at a given moment in time. For example,with respect to the self-capacitance scan described with reference toFIGS. 6C-6D and FIG. 7B, the maximum number of sense channels in sensecircuitry 808 to which switching circuit 806 a's touch node electrodes802 will be coupled at a given moment in time can be eight: one each forthe four complete supernodes coupled to switching circuit 806 a, and oneeach for the four partial supernodes coupled to switching circuit 806 a.Therefore, interconnect lines 820 a (and thus traces 810 a) can becomprised of four lines, and interconnect lines 822 a (and thus traces810 b) can be comprised of four lines, for a total of eight interconnectlines that extend across substantially the entire width of switchingcircuit 806 a. The preceding discussion can apply analogously toswitching circuits 806 b, 806 c and 806 d.

With larger touch screens that include more touch node electrodes 802,and with more complicated touch screen scan configurations, the numberof such interconnect lines can be substantially more than thoseillustrated in FIG. 8B. For example, FIG. 8C illustrates anotherexemplary switching circuit 806 configuration in which switchingcircuits have three sets of interconnect lines according to examples ofthe disclosure. The configuration of FIG. 8C can be substantially thatof FIG. 7C. Specifically, switching circuit 806 a can be coupled totouch node electrodes 802 in supercolumns 814 a and 814 b and part ofsupercolumn 814 c of supernodes, switching circuit 806 b can be coupledto touch node electrodes in part of supercolumns 814 c and 814 e andsupercolumn 814 d of supernodes, switching circuit 806 c can be coupledto touch node electrodes in part of supercolumns 814 e and 814 g andsupercolumn 814 f of supernodes, and switching circuit 806 d can becoupled to touch node electrodes in part of supercolumn 814 g andsupercolumns 814 h and 814 i of supernodes, as previously described withreference to FIG. 7C. Respective switching circuits 806 can be coupledto touch node electrodes 802 via 144 traces 804, as described above withreference to FIG. 7C. Further, respective switching circuits 806 can becoupled to respective sense channels in sense circuitry 808 via sensetraces 810. In some examples, switching circuits 806 can share sensetraces 810. For example, switching circuit 806 a can be coupled to eightsense channels in sense circuitry 808 via eight dedicated sense traces810 a and 810 b, and can also be coupled to another four sense channelsin the sense circuitry via four shared traces 810 c that can be sharedwith switching circuit 806 b. Switching circuit 806 b can be coupled tofour sense channels in sense circuitry 808 via shared traces 810 c, foursense channels in the sense circuitry via four dedicated sense traces810 d, and can also be coupled to another four sense channels in thesense circuitry via four shared traces 810 e that can be shared withswitching circuit 806 c. Switching circuits 806 c and 806 d can becoupled to sense channels in sense circuitry 808 in manners analogous tothose described with reference to switching circuits 806 a and 806 b,above.

Switching circuits 806 can include interconnect lines 820, 822 and 824a, 824 b, 824 c and 824 d (referred to collectively as 824) that canfacilitate the coupling of touch node traces 804 to respective ones oftraces 810. Focusing on switching circuit 806 a (switching circuits 806b, 806 c and 806 d can be similarly structured), the switching circuitcan include interconnect lines 820 a, 822 a and 824 a. Interconnectlines 820 a can be coupled to respective ones of traces 810 a,interconnect lines 822 a can be coupled to respective ones of traces 810b, and interconnect lines 824 a can be coupled to respective ones ofshared traces 810 c that can be shared with switching circuit 806 b andfurther coupled to interconnect lines 824 b in switching circuit 806 b.Touch node traces 804 a can then be selectively coupled to respectiveones of interconnect lines 820 a, 822 a and 824 a so as to couple touchnode electrodes 802 with appropriate traces 810 a, 810 b and 810 c (andthus with appropriate sense channels in sense circuitry 808) accordingto desired touch screen operation (e.g., according to any touch screenscan configuration, such as described with reference to FIGS. 6A-6D).

In some examples, interconnect lines 820 a, 822 a and 824 a can extendacross substantially the entire width of switching circuit 806 a.Further, although illustrated as single lines, it is understood thatinterconnect lines 820 a, 822 a and 824 a can each be comprised ofmultiple lines—specifically, a sufficient number of lines so as to allowfor implementation of desired touch screen scan configurations. Forexample, the total number of lines in interconnect lines 820 a, 822 aand 824 a can correspond to the maximum number of sense channels insense circuitry 808 to which the touch node electrodes 802 to whichswitching circuit 806 a is coupled will be coupled at a given moment intime. For example, with respect to the self-capacitance scan describedwith reference to FIGS. 6C-6D and FIG. 7C, the maximum number of sensechannels in sense circuitry 808 to which switching circuit 806 a's touchnode electrodes 802 will be coupled at a given moment in time can betwelve: one each for the eight complete supernodes coupled to switchingcircuit 806 a, and one each for the four partial supernodes coupled toswitching circuit 806 a. Therefore, interconnect lines 820 a (and thustraces 810 a) can be comprised of four lines, interconnect lines 822 a(and thus traces 810 b) can be comprised of four lines, and interconnectlines 824 a (and thus traces 810 c) can be comprises of four lines, fora total of twelve interconnect lines that extend across substantiallythe entire width of switching circuit 806 a. The preceding discussioncan apply analogously to switching circuits 806 b, 806 c and 806 d. Asshown above, with larger touch screens that include more touch nodeelectrodes 802, and with more complicated touch screen scanconfigurations, the number of such interconnect lines can besubstantially more than those illustrated in FIG. 8C. Thus, it can bebeneficial to reduce the number of interconnect lines that extend acrosssubstantially the entire width of switching circuits 806 to reduce thesize and complexity of the switching circuits, and to save cost inmanufacturing the switching circuits. Further, in some examples, due tospecifics of the touch screen scan configurations utilized by the touchscreen of the disclosure, certain touch node electrodes 802 may not needto be coupled to certain traces 810 during any touch screen scan, andthus not all touch node electrodes 802 on the touch screen may need tohave access to all of interconnect lines 820, 822 and 824. Thus,interconnect lines 820, 822 and 824 need not extend across substantiallythe entirety of switching circuits 806, as will be shown below.

FIG. 8D illustrates an exemplary switching circuit 806 configuration inwhich switching circuits have three sets of interconnect lines accordingto examples of the disclosure. The touch screen 800 configuration ofFIG. 8D can be substantially that of FIGS. 8C and 7C. Specifically,switching circuit 806 a can be coupled to touch node electrodes 802 insupercolumns 814 a and 814 b and part of supercolumn 814 c ofsupernodes, switching circuit 806 b can be coupled to touch nodeelectrodes in part of supercolumns 814 c and 814 e and supercolumn 814 dof supernodes, switching circuit 806 c can be coupled to touch nodeelectrodes in part of supercolumns 814 e and 814 g and supercolumn 814 fof supernodes, and switching circuit 806 d can be coupled to touch nodeelectrodes in part of supercolumn 814 g and supercolumns 814 h and 814 iof supernodes, as previously described with reference to FIG. 7C.Respective switching circuits 806 can be coupled to touch nodeelectrodes 802 via 144 traces 804, as described above with reference toFIG. 7C. Further, respective switching circuits 806 can be coupled torespective sense channels in sense circuitry 808 via sense traces 810.In some examples, switching circuits 806 can share sense traces 810. Forexample, switching circuit 806 a can be coupled to eight sense channelsin sense circuitry 808 via eight dedicated sense traces 810 a and 810 b,and can also be coupled to another four sense channels in the sensecircuitry via four shared traces 810 c that can be shared with switchingcircuit 806 b. Switching circuit 806 b can be coupled to four sensechannels in sense circuitry 808 via shared traces 810 c, four sensechannels in the sense circuitry via four dedicated sense traces 810 d,and can also be coupled to another four sense channels in the sensecircuitry via four shared traces 810 e that can be shared with switchingcircuit 806 c. Switching circuits 806 c and 806 d can be coupled tosense channels in sense circuitry 808 in manners analogous to thosedescribed with reference to switching circuits 806 a and 806 b, above.

Switching circuits 806 can include interconnect lines 850 a, 850 b, 850c and 850 d (referred to collectively as 850), 852 a, 852 b, 852 c and852 d (referred to collectively as 852) and 854 a, 854 b, 854 c and 854d (referred to collectively as 854) that can facilitate the coupling oftouch node traces 804 to respective ones of traces 810. Focusing onswitching circuit 806 a (the discussion that follows can similarly applyto switching circuits 806 b, 806 c and 806 d), interconnect lines 850 acan extend across a portion of switching circuit 806 a, and interconnectlines 854 a can extend across a remaining portion of the switchingcircuit, as illustrated. In some examples, interconnect lines 850 a and854 a can be horizontally aligned lines with a break between the two toform the resulting separate interconnect lines. Interconnect lines 852 acan extend across substantially the entirety of switching circuit 806 a.Touch node traces 804 a can couple switching circuit 806 a's touch nodeelectrodes 802 to one or more of interconnect lines 850 a, 852 a and 854a. Thus, the configuration of switching circuit 806 a in FIG. 8D caninclude the same number of separate interconnect lines (lines 850 a, 852a and 854 a) as the configuration of switching circuit 806 a in FIG. 8C(lines 820 a, 822 a and 824 a). However, interconnect lines 850 a, 852 aand 854 a in switching circuit 806 a in FIG. 8D can occupy the space oftwo interconnect lines extending across substantially the entirety ofthe switching circuit, whereas interconnect lines 820 a, 822 a and 824 ain switching circuit 806 a in FIG. 8C can occupy the space of threeinterconnect lines extending across substantially the entirety of theswitching circuit. Thus, the interconnect line configuration of FIG. 8Dcan occupy approximately 33% less space in switching circuits 806 thanthe interconnect line configuration of FIG. 8C, while maintainingdesired touch screen operation. Therefore the switching circuits canrequire less width and area, enabling thinner display border areas andreduced cost.

In some examples, all of traces 804 a can have access to (i.e., can becoupled to) all of interconnect lines 850 a, 852 a and 854 a. In someexamples, interconnect lines 850 a may only have access to a firstportion of traces 804 a (e.g., because interconnect lines 850 a may onlyextend across a portion of switching circuit 806 a), interconnect lines854 a may only have access to a second portion of traces 804 a (e.g.,because interconnect lines 854 a may only extend across a portion ofswitching circuit 806 a), and interconnect lines 852 a may have accessto all of traces 804 a (e.g., because interconnect lines 852 a mayextend across the entirety of switching circuit 806 a).

In general, the number of switches in a given switching circuit (asdescribed throughout this disclosure) can be optimized based on thenumber of full super columns and partial super columns the switchingcircuit supports. For example, two interconnect line segments (e.g.,interconnect lines 850 b and 854 b), one for each partial super column,can be side by side in the switching circuit, while the remaining fullsuper columns (if any) may require an interconnect line/matrix thatextends substantially across the entire width of the switching circuit(e.g., interconnect lines 852 b), as shown in the example of FIG. 8D.For self-capacitance scanning, the total number of interconnectlines/sense channels needed per partial or full super column can beNsns_scol=Nnode_scol/Nsteps, where Nnode_scol is the number of nodes persuper column, and Nsteps is the number of scan steps in theself-capacitance scan. The depth of the interconnect line/matrix segment(i.e., the number of interconnect lines per segment) can beNsw=(Npartial/2+Nfull)*Nnode_scol, where Npartial is the number ofpartial super columns (e.g., generally 2) supported by a given switchingcircuit, and Nfull is the number of full super columns supported by thegiven switching circuit.

As described above with respect to FIGS. 6A-6D, in some examples, thetouch screen of the disclosure may need to accommodate a variety ofdifferent touch screen scan configurations. Therefore, it can bebeneficial for the touch screen, and in particular the switchingcircuits of the touch screen, to be sufficiently flexible to allow for avariety of touch screen scan configurations to be implemented on thetouch screen. FIGS. 9-11 illustrate various switching circuitconfigurations that allow for such flexibility.

FIG. 9A illustrates an exemplary memory-based switching circuit 906configuration according to examples of the disclosure. Switching circuit906 can correspond to any of the switching circuits described in thisdisclosure, including switching circuits 506 in FIG. 5B, switchingcircuits 706 in FIGS. 7A-7C and/or switching circuits 806 in FIGS.8A-8D. Switching circuits 906 can be coupled to sense circuitry 908 in avariety of ways, as will be described below. Switching circuit 906 caninclude pixel mux blocks (“PMBs”) 918 a-918N (referred to collectivelyas 918). Each PMB 918 can be coupled to a particular touch nodeelectrode on the touch screen of the disclosure (not illustrated). Forexample, PMB 918 a can be coupled to touch node electrode 1, PMB 918 bcan be coupled to touch node electrode 2, and PMB 918N can be coupled totouch node electrode N. For the purposes of this disclosure, touch nodeelectrodes can be numbered from top to bottom, then from left to right,on the touch screen, as illustrated in FIG. 9B, though it is understoodthat the particular touch node electrode numbering scheme used can bemodified within the scope of this disclosure. Thus, moving from PMB 918a to PMB 918 b (i.e., moving horizontally to the right across switchingcircuit 906) can correspond to moving from touch node electrode 1 totouch node electrode 2 (i.e., moving vertically downwards across thetouch screen). It is understood that while FIG. 9B illustrates a touchscreen with 144 touch node electrodes, other touch screen configurationsare also within the scope of the disclosure, including touch screenswith 320 touch node electrodes (e.g., a five by four supernode touchscreen having 20 columns of touch node electrodes, and 16 rows of touchnode electrodes). There can be as many PMBs 918 in switching circuit 906as there are touch node electrodes to which the switching circuit iscoupled. For example, referring back to FIG. 7A, if switching circuit906 corresponds to switching circuit 706 a, then switching circuit 906can include 64 PMBs 918, each PMB coupled to a respective one of the 64touch node electrodes to which the switching circuit is coupled. Theabove-provided numbers are exemplary only, and it is understood that theswitching circuit 906 architecture of FIG. 9A can be adapted to operatewith any number of touch node electrodes. Switching circuit 906 can alsoinclude various memories 912, 914 and 916 and interface 904, all ofwhich will be described in more detail later.

Sense circuitry 908 can be coupled to switching circuit 906 at lines 902a-902M (referred to collectively as 902). Lines 902 can correspond tointerconnect lines 820, 822, 830, 832, 840, 842, 844, 850, 852 and/or854 in FIGS. 8A-8D, for example. Lines 902 can transmit any number ofsignals to and/or from sense circuitry 908. For example, one or more oflines 902 can be coupled to particular sense channels in sense circuitry908, one or more of lines 902 can be coupled to a common voltage sourceat which to bias touch node electrodes during a display phase of thetouch screen (e.g., a Vcom voltage source) in the sense circuitry, oneor more of lines 902 can be coupled to a Vbias voltage source (e.g., asdescribed with reference to FIGS. 6A-6D) in the sense circuitry, and/orone or more of lines 902 can be coupled to a Vdrive voltage source(e.g., as described with reference to FIGS. 6A-6D) in the sensecircuitry. While three such lines—lines 902 a, 902 b and 902M—areillustrated in FIG. 9A, fewer or more lines can be utilized inaccordance with the examples of the disclosure.

PMBs 918 can include a number of switches (e.g., switches 922 a-922N(referred to collectively as 922), 924 a-924N (referred to collectivelyas 924) and 926 a-926N (referred to collectively as 926)) equal to thenumber of lines 902 in switching circuit 906. Using these switches 922,924 and 926, PMBs 918 can selectively couple their respective touch nodeelectrodes to any one of lines 902. For example, PMB 918 a can coupletouch node electrode 1—to which PMB 918 a can be coupled—to line 902M byclosing switch 926 a while leaving switches 922 a and 924 a open. Inthis way, touch node electrode 1 can be coupled to any signal that canexist on lines 902, such as those discussed above. PMBs 918 b through918N can similarly selective couple their respective touch nodeelectrodes to any one of lines 902, thereby providing significantflexibility in which signals can get coupled to which touch nodeelectrodes via switching circuit 906. In some examples, PMBs 918 caninclude fewer or more switches 922, 924, 926 than the number of lines902 in switching circuit 906, depending on the touch screen scanconfigurations to be implemented by the touch screen (e.g., as describedwith reference to FIGS. 6A-6D). For example, a given PMB 918 (and thus agiven touch node electrode) may not need to be coupled to a particularline 902, because the touch screen scan configurations implemented onthe touch screen may specify that the PMB's corresponding touch nodeelectrode need not be so coupled. In such a circumstance, that given PMB918 need not include a switch for coupling that PMB to that particularline 902. Other examples in which the number of switches in the PMBs 918is different from the number of lines 902 in switching circuit 906 aresimilarly contemplated. Control of switches 922, 924 and 926 can beprovided by PMB logic 920 a-920N (referred to collectively as 920) thatcan be included in each PMB 918. The details of this control will now bedescribed.

In addition to being coupled to switching circuit 906 at lines 902,sense circuitry 908 (e.g., a sensing application specific integratedcircuit (ASIC)) can be coupled to bank ID line 910 and interface 904 inthe switching circuit. Bank ID line 910 can be coupled to PMB logic 920,and can be used, by sense circuitry 908, to identify particular PMBs918/bank IDs of interest for use in various touch screen scanoperations, as will be described in this disclosure. Interface 904 canbe an interface (e.g., a serial peripheral interface (SPI)) that canallow for communication between sense circuitry 908 and switchingcircuit 906. Interface 904 can be coupled to memories 912, 914 and 916.Memories 912, 914 and 916 can store information relating to varioustouch screen scan configurations (e.g., touch screen scan configurationsas discussed with respect to FIGS. 6A-6D) that are to be implemented onthe touch screen to which the switching circuit is coupled. Interface904 can facilitate exchange of this touch screen scan information fromsense circuitry 908 to memories 912, 914 and 916, so that the sensecircuitry can control the touch screen scan information stored on thememories. In some examples, sense circuitry 908 can update or change thetouch screen scan information stored on memories 912, 914 and 916, whichcan give the sense circuitry substantial flexibility in what touchscreen scan configurations are to be implemented on the touch screen.For example, during a power-up of the touch screen (or at any timeduring touch screen operation), sense circuitry 908 can populatememories 912, 914 and 916 with touch screen scan information based onthe touch screen scans to be implemented on the touch screen. The touchscreen scan information stored on memories 912, 914 and 916 can be usedby PMB logic 920 on PMBs 918 to control the states of switches 922, 924and 926 in the PMBs. Thus, the touch screen scan information stored onmemories 912, 914 and 916 can control the lines 902 to which touch nodeelectrodes on the touch screen will be coupled via PMBs 918 duringvarious touch screen scans.

In some examples, memories 912, 914 and 916 can be combined into asingle memory or a different number of memories than as described here.However, for the purposes of the disclosure, switching circuit 906 caninclude three memories: 912, 914 and 916, as illustrated. Each ofmemories 912, 914 and 916 can be coupled to PMB logic 920 in PMBs 918.Memory 916 can be referred to as a “bank ID memory.” Bank ID memory 916can include identification information (e.g., a “bank ID”) for each PMB918 in switching circuit 906; this identification information canprovide an identifier—not necessarily a unique identifier—for each PMBin the switching circuit. In some examples, the bank IDs assigned toeach PMB 918 in bank ID memory 916 can correspond to the supernodeconfiguration utilized during one or more touch screen scanconfigurations on the touch screen (e.g., the touch screen scanconfigurations as described with reference to FIGS. 6A-6D).Specifically, every touch node electrode in a supernode, and thus thosetouch node electrodes' corresponding PMBs 918, can be assigned the samebank ID. For example, PMB 918 a can be assigned a bank ID of 1, PMB 918b can also be assigned a bank ID of 1, and PMB 918N can be assigned abank ID of 16. The above numbers are exemplary only, and do not limitthe scope of the disclosure relating to bank ID memory 916 storingidentification information for each PMB 918 in switching circuit 906. Inthis way, a bank ID can refer to a unique supernode on the touch screen,and can provide a simple way to identify all touch node electrodesincluded in a supernode on the touch screen. For example, referring backto FIG. 7A, all of the touch node electrodes 702 in supernode 703, andthus the PMBs coupled to those touch node electrodes, can be assigned abank ID of 1. In some examples, bank IDs can be numbered consecutivelyfrom top to bottom and from left to right on touch screen 700. In suchexamples, supernode 703 can be assigned a bank ID of 1, as describedabove, the supernode below supernode 703 can be assigned a bank ID of 2,the supernode below that can be assigned a bank ID of 3, and the finalsupernode in that column of supernodes can be assigned a bank ID of 4.The top supernode in column 714 of supernodes can be assigned a bank IDof 5, and the assignments of bank IDs to supernodes can continue asdescribed above. The bottom-right supernode on touch screen 700 can beassigned a bank ID of 16. In turn, the PMBs 918 in switching circuit 906to which touch node electrodes in the above supernodes are coupled canbe assigned the same bank ID as is assigned to their correspondingsupernodes. Additional information about how bank IDs can be utilized bythe touch screen will be provided later.

Memory 914 can be referred to as a “channel switch configurationmemory.” Channel switch configuration memory 914 can include switchcontrol information for switches 922, 924 and 926 in PMBs 918 for one ormore scan types. For example, as discussed with reference to FIGS.6A-6D, the touch screen of the disclosure can implement five scan types:a pen detection scan type, a pen row scan type, a pen column scan type,a mutual capacitance scan type and a self-capacitance scan type. Otherscan types are also possible, and the scan types provided are providedby way of example only. Each of these scan types can require thatdifferent touch node electrodes on the touch screen be coupled todifferent signals/sense channels in sense circuitry 908. For example, asillustrated in FIGS. 6A-6D, in the mutual capacitance scan type, in acollection of 2×2 touch node electrodes, one touch node electrode may bedriven and sensed (and thus can be coupled to a sense channel in sensecircuitry), one touch node electrode made be driven but not sensed (andthus can be coupled to driving circuitry), and the remaining two touchnode electrodes may be biased at a reference voltage (and thus can becoupled to bias circuitry). Thus, channel switch configuration memory914 can include switch control information corresponding to the mutualcapacitance scan type for all of the PMBs 918 included in switch circuit906, such that PMB logic 920 on the PMBs can, based on the switchcontrol information in the channel switch configuration memory, controlswitches 922, 924 and 926 to ensure that corresponding touch nodeelectrodes are coupled to the appropriate signals/sense channels forimplementing the mutual capacitance scan type. Channel switchconfiguration memory 914 can similarly include other switch controlinformation for other scan types that are to be implemented on the touchscreen of the disclosure, such as a pen detection scan type, a pen rowscan type, a pen column scan type and a self-capacitance scan type.Thus, channel switch configuration memory 914 can define how touch nodeelectrodes are mapped to sense channel(s) in sensing circuitry 908.

Some scan types may include more than one scan step. For example, theself-capacitance scan type can include four self-capacitance scan steps,as illustrated in FIGS. 6A-6D. Each of these scan steps can requiredifferent PMB 918 switch configurations, because in each of these scansteps, touch node electrodes can be required to be coupled to differentsignals/sense channels in sense circuitry 908. Memory 912 can bereferred to as “scan step memory.” Scan step memory 912 can, similar tochannel switch configuration memory 914, include switch controlinformation corresponding to the various scan steps to be implemented onthe touch screen for all of the PMBs 918 included in switch circuit 906,such that PMB logic 920 on the PMBs can, based on the switch controlinformation in the scan step memory, control switches 922, 924 and 926to ensure that corresponding touch node electrodes are coupled to theappropriate signals/sense channels for implementing the various scansteps. In particular, scan step memory 912 can indicate whether a givenPMB 918 (and thus its corresponding touch node electrode) should becoupled to a collection of global signals (e.g., Vdrive, Vcom or Vbias)or a sense channel for a given scan step. If a PMB 918 is to be coupledto a sense channel, channel switch configuration memory 914 can specifywhich sense channel, as described above. For example, focusing on scanstep 1 of the self-capacitance scan type illustrated in FIG. 6C, scanstep memory 912 can include switch control information indicating that:the PMB 918 corresponding to the upper-left touch node electrode inconfiguration 658 should be coupled to a sense channel in sensecircuitry 908 (and channel switch configuration memory 914 can indicateto which sense channel the touch node electrode should be coupled), thePMB corresponding to the lower-right touch node electrode inconfiguration 658 should be coupled to bias circuitry in the sensecircuitry, and the PMBs corresponding to the upper-right and lower-lefttouch node electrodes in configuration 658 should be coupled to drivingcircuitry in sense circuitry 908. Scan step memory 912 can also includeswitch control information for the remaining three scan steps of theself-capacitance scan type, and other scan steps that may be implementedby the touch screen of the disclosure (e.g., scan steps of the pendetection scan type).

Thus, bank ID memory 916, channel switch configuration memory 914 andscan step memory 912, together, can include all of the switch controlinformation needed for PMBs 918 to properly implement all of the varioustouch screen scan configurations of the touch screen. During touchscreen operation, sense circuitry 908 (e.g., sensing ASIC) can simplyprompt switching circuit 906 to implement a particular scan type and/orscan step, and bank ID memory 916, channel switch configuration memory914 and scan step memory 912 can operate in conjunction with PMB logic920 in PMBs 918 to effectuate the prompted scan type and/or scan step.

Display subsystem 948 (e.g., systems for controlling display functionsof the touch screen) can be coupled to switching circuit 906 at BSYNCline 911, which can be coupled to PMB logic 920 in PMBs 918. Displaysubsystem 948 can assert BSYNC=HIGH and BSYNC=LOW to indicate whetherthe touch screen is in a touch mode or a display mode, which PMB logic920 can utilize in making various determinations about the states ofswitches 922, 924 and 926, as will be described later in more detail.

FIG. 9C illustrates an exemplary logical block diagram for a switchingcircuit 906 including PMB logic 920 (e.g., PMB logic 920 a, 920 b, 920N)distributed across the switching circuit according to examples of thedisclosure. Switching circuit 906 may contain a variety of registers940. Registers 940 can include a channel switch configuration register942 to store a pointer into channel switch configuration memory 914(described above), and a scan step configuration register 944 to store apointer into scan step memory 912 (described above). A bank of registers946 can be dedicated to store global bank IDs to identify PMBs 918determined for pen row/column scanning after a pen detection scan, aspreviously described. Display subsystem 948 can furnish a BSYNC signalto switching circuit 906, which can be used to determine how toconfigure the PMBs 918 during touch and display modes according to logicin PMB logic decoder 920, as will be illustrated in FIG. 9D. In someexamples, channel switch configuration register 942 and scan stepconfiguration register 944 can be configured via settings stored in abank of scan sequence registers 952 (e.g., one scan sequence registerfor each scan step). For example, at the beginning of a touch screenscan, scan step counter 954 can be reset, and touch sensing ASIC 908 canfurnish a STEP_CLK to scan step counter 954 to advance the scan stepcounter, which can, in turn, cause retrieval of channel switch and scanstep configurations from the scan sequence registers 952 in preparationfor the next scan step. For example, advancing scan step counter 954 canprovide an index/address to scan step address register 958, which canstore a pointer into scan step sequence registers 952 corresponding tothe current scan being performed. Each successive scan step count fromscan step counter 954 can cause the pointer to cycle to the nextappropriate scan step sequence register 952 corresponding to the currentscan step being performed. Channel switch configuration register 942 andscan step configuration register 944 can, then, be populated with theappropriate switch configuration information from scan step sequenceregisters 952 for the current scan step. Scan mode register 960 canstore mode information (e.g., as described with reference to FIG. 11C)to designate which of a self-capacitance, mutual capacitance, pendetection, pen row and pen column scans should be performed. Globalswitch enable register 962 can designate whether or not the switches inswitching circuit 906 should be configured based on the switchconfiguration information in channel switch configuration register 942and/or scan step configuration register 944, and bank ID enable registercan designate whether or not bank ID-based scanning for pen row and pencolumn scans should be performed. In an example switching circuit 906configuration that uses shift registers to transfer switch configurationinformation from one PMB 918 to another, a PMB shift count register 956can store the number of PMBs 918 by which to shift the above-describedPMB configuration to other PMBs in switching circuit 906 (e.g., asdescribed with reference to FIG. 12).

An exemplary logic table for PMB logic decoder 920 illustrating itsexemplary operation is shown below. In the table, PMB SENSE, PMB VDRIVE,PMB VB and PMB VC columns can correspond to output signals from PMBlogic decoder 920, while the remaining columns can correspond to inputsignals to the PMB logic decoder. PMB SENSE being high (H) cancorrespond to a command to configure a PMB's switches based on switchconfiguration provided from the channel switch configuration memory 914.Similarly, PMB VDRIVE, PMB VB and PMB VC being high (H) can correspondto a command to close a PMB's Vdrive, Vbias and Vcom switches,respectively, to implement the various scans described in thisdisclosure. In the table, below, a low (L) BSYNC value can indicate atouch screen display mode, which can cause a PMB VC switch (e.g., one ofswitches 922, 924, 926 in FIG. 9A) to be engaged to dischargecorresponding touch node electrodes to a display voltage, VCOM, from thevoltage levels maintained during the touch mode. A high (H) BSYNC valuecan, correspondingly, indicate a touch screen touch mode. The globalchannel switch enable bit (GLB_CH_SW_EN) can cause the PMB switchescoupled to sense channels to be enabled according to the programmedchannel switch configuration in channel switch configuration memory 914and/or channel switch configuration register 942. This feature canprimarily be used in the touch screen pen detect mode. BANK_ID_EN can beasserted HIGH prior to sending the global BANK IDs to the switchingchip, which can identify the BANK IDs in which pen row/column scans areto be performed. Setting BANK_ID_EN high can also cause matching PMBs(e.g., PMBs in which the programmed BANK_ID matches the provided globalBANK ID) to enable their switches as programmed through the channelswitch configuration memory, and can be used during pen row and/orcolumn scans.

PMB SENSE Switch (as programmed in channel PMB Scan switch VDRIVE PMBPMB Step configuration Switch VB VC GLB_BANK_ID_GLB[5:0] GLB_CH_SW_ENBANK_ID_EN Config. BSYNC memory) Enable Switch Switch X H X X H H L L LBANK_ID L H X H H L L L ~BANK_ID L H X H L L H L X L L 2′B00 H L L H L XL L 2′B01 H L H L L X L L 2′B10 H H L L L X L L 2'B11 H H L L L X L L2′B10 H L L H L X L L 2′B11 H L L H L X L L X L L L L H

FIG. 10A illustrates an exemplary first scan step of a self-capacitancescan type on touch screen 1000 according to examples of the disclosure.Touch screen 1000 can correspond to any of the touch screens describedin this disclosure. It is understood that while FIGS. 10A, 10B and 10Dillustrate a touch screen 1000 with 144 touch node electrodes 1002(e.g., touch node electrodes 1002 a-1002 f), other touch screenconfigurations are also within the scope of the disclosure, includingtouch screens with 320 touch node electrodes (e.g., a five by foursupernode touch screen having 20 columns of touch node electrodes, and16 rows of touch node electrodes, and coupled to four switching circuits1006, as described with reference to FIG. 8B). The discussion below canapply analogously to such other touch screens. As described withreference to FIGS. 6A-6D, in some examples, touch screen 1000 canimplement a self-capacitance scan type having four scan steps. In thefirst scan step, focusing on a 2×2 collection of touch node electrodes1002, a top-left touch node electrode can be driven and sensed, abottom-right touch node electrode can be biased at a reference voltage,and top-right and bottom-left touch node electrodes can be driven butnot sensed. Further, in some examples, touch screen 1000 can be scannedin portions rather than all at once, as illustrated in FIG. 6D. Thus, asillustrated in FIG. 10A, portion 1001 of touch screen 1000 can bescanned in the first scan step of the self-capacitance scan type, asdescribed. Touch node electrodes 1002 labeled with sense channel numbers(e.g., S1, S2, S3, S4, etc.) can indicate touch node electrodes that arebeing driven and sensed, and the number can indicate by which sensechannel in sense circuitry 1008 the touch node electrode is being drivenand sensed. For example, touch node electrode 1002 a, which is labeledwith “S1”, can be driven and sensed by a different sense channel insense circuitry 1008 than touch node electrode 1002 b, which is labeledwith “S2”.

FIG. 10B illustrates an exemplary second scan step of a self-capacitancescan type on touch screen 1000 according to examples of the disclosure.As described with reference to FIGS. 6A-6D, the second scan step of theself-capacitance scan type can result from a clockwise rotation of 2×2groups of touch node electrodes 1002 in the first scan step of theself-capacitance scan type, as illustrated in FIG. 10B.

Because switching circuits 1006 (e.g., switching circuits 1006 a-1006 c)can have memory (e.g., memories 912, 914 and 916 in FIG. 9A) thatalready includes the specific switch control information forimplementing the first scan step of FIG. 10A and the second scan step ofFIG. 10B on touch screen 1000, sense circuitry 1008 need only prompt theswitching circuits to implement the first and second scan steps—theswitching circuits can then autonomously configure their respective PMBs(e.g., PMBs 918 in FIG. 9A) to couple their respective touch nodeelectrodes 1002 to the appropriate signals/sense channels in the sensecircuitry.

FIG. 10C illustrates exemplary commands transmitted by sense circuitry1008 to switching circuits 1006 for implementing the first and secondscan steps of FIGS. 10A and 10B according to examples of the disclosure.In step 1030, the display subsystem can assert BSYNC=HIGH to indicatetouch mode operation, and to therefore pre-charge touch node electrodesfrom a display voltage level VCOM to a bias voltage for the upcomingtouch screen scans (e.g., Vbias) by enabling switches coupled to Vbiasin the PMBs. Next, sense circuitry 1008 can transmit to switchingcircuits 1006 a, 1006 b and 1006 c command 1031, which can include apointer into channel switch configuration memory for selecting theappropriate channel switch configuration for a self-capacitance scan oftouch screen 1000. Specifically, command 1031 can indicate that theupcoming touch screen scan will have a self-capacitance scan type, aspreviously described. Following command 1031, sense circuitry 1008 cantransmit to switching circuits 1006 a, 1006 b and 1006 c command 1032indicating that the upcoming touch screen 1000 scan will be the firstscan step of the self-capacitance scan type (e.g., as described withreference to FIG. 10A). For example, command 1032 can include a pointerinto scan step configuration memory for selecting the appropriate scanstep configuration for the first scan step of the self-capacitance scantype. In response to command 1032, switching circuits 1006 can configuretheir respective PMBs as described previously such that the touch nodeelectrodes 1002 coupled to the switching circuits can be coupled toappropriate signals/sense channels in sense circuitry 1008 to implementthe first scan step of the self-capacitance scan type. For example,referring back to FIG. 10A, in response to command 1032, switchingcircuit 1006 a can configure its respective PMBs such that touch nodeelectrode 1002 a is coupled to sense channel 1 in sense circuitry 1008and touch node electrode 1002 b is coupled to sense channel 2 in thesense circuitry, switching circuit 1006 b can configure its respectivePMBs such that touch node electrode 1002 c is coupled to sense channel 5in the sense circuitry and touch node electrode 1002 d is coupled tosense channel 6 in the sense circuitry, and switching circuit 1006 c canconfigure its respective PMBs such that touch node electrode 1002 e iscoupled to sense channel 9 in the sense circuitry and touch nodeelectrode 1002 f is coupled to sense channel 10 in the sense circuitry.Switching circuits 1006 a, 1006 b and 1006 c can similarly configuretheir remaining PMBs such that the remaining touch node electrodes 1002are coupled to appropriate signals/sense channels in sense circuitry1008, as illustrated in FIG. 10A. Sense circuitry 1008 can then performthe first scan step of the self-capacitance scan type in region 1001 oftouch screen 1000 at step 1033.

After sense circuitry 1008 has completed the first scan step of theself-capacitance scan type, it can transmit to switching circuits 1006a, 1006 b and 1006 c via respective interfaces (e.g., interface 904 inFIG. 9A) command 1034 indicating that the upcoming touch screen 1000scan will be the second scan step of the self-capacitance scan type(e.g., as described with reference to FIG. 10B), similar to as describedwith reference to command 1032. In response to command 1034, switchingcircuits 1006 can configure their respective PMBs as describedpreviously such that the touch node electrodes 1002 coupled to theswitching circuits can be coupled to appropriate signals/sense channelsin sense circuitry 1008 to implement the second scan step of theself-capacitance scan type, as illustrated in FIG. 10B. Sense circuitry1008 can then perform the second scan step of the self-capacitance scantype in region 1001 of touch screen 1000 at step 1035. Additional scansteps (e.g., the third and fourth scan steps) of the self-capacitancescan type can similarly be implemented, at step 1036, with commandsanalogous to those discussed above. At 1037, the display subsystem canassert BSYNC=LOW indicating the touch period is completed, and thuscausing touch node electrodes to be discharged from the bias voltageused during the self-capacitance scans above to a common voltage (e.g.,Vcom) used during display operation by enabling switches coupled to Vcomin the PMBs. The touch integration time (e.g., the touch scan time) canbe adjusted so as to ensure that the touch scan(s) complete before theBSYNC=LOW assertion. In this way, sense circuitry 1008 can implement avariety of touch screen scans—including relatively complex scans—byissuing simple commands to switching circuits 1006, and communicationoverhead between the sense circuitry and the switching circuits can berelatively low.

As another example, FIG. 10D illustrates an exemplary pen row scan typeperformed in supernode 1012 of touch screen 1000 according to examplesof the disclosure. As described with references to FIGS. 6A-6D, in someexamples, touch screen 1000 can implement a pen row scan type inresponse to detecting the presence of a pen or stylus on the touchscreen during a pen detection scan. For example, as describedpreviously, if a pen or stylus is detected in supernode 1010 on touchscreen 1000, pen row and pen column scans can be initiated in thesupernode in which the pen or stylus was detected (e.g., supernode1010), as well as the supernodes surrounding the supernode in which thepen or stylus was detected (e.g., supernodes 1012, 1014, 1016, 1018,1020, 1022, 1024 and 1026). The process by which such pen row and pencolumn scans can be performed in one supernode can be substantially thesame as the process by which such pen row and pen column scans can beperformed in another supernode—thus, the discussion that follows willfocus on a pen row scan performed in supernode 1012, understanding thatthe process can similarly apply to performing pen row scans in othersupernodes, as well as pen column scans in supernode 1012 or othersupernodes.

As illustrated in FIG. 10D, a pen row scan can be performed in supernode1012. Touch node electrodes 1002 labeled with sense channel numbers(e.g., S1, S2, S3) can indicate touch node electrodes that are beingsensed, and the number can indicate by which sense channel in sensecircuitry 1008 the touch node electrode is being sensed. For example,the top row of touch node electrodes 1002 in supernode 1012 can becoupled to sense channel 1 in sense circuitry 1008, the middle row oftouch node electrodes in supernode 1012 can be coupled to sense channel2 in the sense circuitry, and the bottom row of touch node electrodes insupernode 1012 can be coupled to sense channel 3 in the sense circuitry.It is understood that the precise numbering of sense channels providedis exemplary only, and does not limit the scope of the disclosure.Switching circuits 1006 can configure their respective PMBs (e.g., PMBs918 in FIG. 9A) to couple their respective touch node electrodes 1002 tothe appropriate signals/sense channels in sense circuitry 1008 in orderto implement the pen row scan illustrated, as well as other pen-relatedscans on the touch screen, as will be described below.

FIG. 10E illustrates exemplary commands transmitted by sense circuitry1008 to switching circuits 1006 for implementing pen scans according toexamples of the disclosure. In step 1040, the display subsystem canassert BSYNC=HIGH to indicate touch mode, and to therefore pre-chargetouch node electrodes from a display voltage VCOM to a bias voltage forthe upcoming touch screen scans (e.g., Vbias) by enabling switchescoupled to Vbias in the PMBs. Next, sense circuitry 1008 can transmit toswitching circuits 1006 a, 1006 b and 1006 c command 1041, which caninclude a pointer into channel switch configuration memory for selectingthe appropriate channel switch configuration for pen detection scans.Specifically, command 1041 can specify that the upcoming touch screenscan will be a pen detection scan, as previously described. Next, sensecircuitry 1008 can perform the pen detection scan at step 1042. At 1043,sense circuitry 1008 can identify addresses of supernodes at and aroundthe touch screen location at which pen activity was detected, and canmap those supernodes to corresponding bank IDs, as previously described.At 1044, sense circuitry 1008 can set the BANK_ID mode bit (to enableBANK ID-based touch scan operation) and the relevant BANK_IDs in theswitching circuits to enable the bank latches of the relevant PMBs(i.e., the PMBs in which pen row and pen column scans are to beperformed). At 1045, sense circuitry 1008 can transmit to switchingcircuits 1006 a, 1006 b and 1006 c command 1045, which can include apointer into channel switch configuration memory for selecting theappropriate channel switch configuration for a pen column scan to beperformed in supernodes having the bank IDs determined at 1043. Inresponse, switching circuits 1006 can configure their respective PMBs asdescribed previously such that the touch node electrodes 1002 coupled tothe switching circuits can be coupled to appropriate signals/sensechannels in sense circuitry 1008 to implement the pen column scan typein the supernodes having the relevant bank IDs, as described withreference to FIG. 6B. At 1046, sense circuitry 1008 can perform the pencolumn scans. After performing the pen column scans, sense circuitry1008 can transmit to switching circuits 1006 a, 1006 b and 1006 ccommand 1047, which can include a pointer into channel switchconfiguration memory for selecting the appropriate channel switchconfiguration for a pen row scan to be performed in supernodes havingthe bank IDs determined at 1043. In response, switching circuits 1006can configure their respective PMBs as described previously such thatthe touch node electrodes 1002 coupled to the switching circuits can becoupled to appropriate signals/sense channels in sense circuitry 1008 toimplement the pen row scan type in the supernodes having the relevantbank IDs, as described with reference to FIG. 6B. At 1048, sensecircuitry 1008 can perform the pen row scans. After performing the penrow scans, the display subsystem can assert BSYNC=LOW indicating thetouch period is completed, and thus causing touch node electrodes to bedischarged from the bias voltage used during the pendetection/column/row scans above to a common voltage (e.g., Vcom) usedduring display operation by enabling switches coupled to Vcom in thePMBs. The pen integration time (e.g., the pen scan time) can be adjustedso as to ensure that the pen scan(s) complete before the BSYNC=LOWassertion.

The switching circuit control and configuration schemes discussed abovecan be used to implement any number of touch screen scans in addition tothose illustrated in FIGS. 10A-10E. FIG. 10F illustrates exemplaryswitching circuit command combinations 1070 that can be utilized toimplement the touch screen scans discussed with reference to FIGS. 6A-6Daccording to examples of the disclosure. Five scan types can besupported by the switching circuits of the disclosure, though other scantypes can similarly be supported. A first scan type can be a mutualcapacitance scan type 1072. The mutual capacitance scan type 1072 can beimplemented with a single command indicating the mutual capacitance scantype is to be performed. No scan step or bank ID commands need betransmitted by the sense circuitry to the switching circuits for themutual capacitance scan type 1072.

A second scan type can be a self-capacitance scan type 1074. Theself-capacitance scan type 1074 can be associated with a number of scansteps—in some examples, 16 scan steps (e.g., four scan steps per bank,with, in some examples, four banks). Thus, the self-capacitance scantype 1074 can be implemented with a command indicating theself-capacitance scan type is to be performed, followed by one or morecommands indicating respective scan steps of the self-capacitance scantype to be performed. No bank ID command need be transmitted by thesense circuitry to the switching circuits for the self-capacitance scantype 1074. In some examples, a bank ID command could be used to specifythat self-capacitance scans should only be performed in the bank IDsspecified in the bank ID command, such as those bank IDs in which (or inproximity to which) touch is detected on the touch sensor panel/touchscreen.

A third scan type can be a pen detection scan type 1076. The pendetection scan type 1076 can be associated with a number of scansteps—in some examples, two scan steps. Thus, the pen detection scantype 1076 can be implemented with a command indicating the pen detectionscan type is to be performed, followed by one or more commandsindicating respective scan steps of the pen detection scan type to beperformed. No bank ID command need be transmitted by the sense circuitryto the switching circuits for the pen detection scan type 1076.

A fourth scan type can be a pen row scan type 1078. The pen row scantype can be performed in any of a number of bank IDs. Thus, the pen rowscan type 1078 can be implemented with a command indicating the pen rowscan type is to be performed, followed by one or more commandsindicating respective bank IDs in which the pen row scan is to beperformed. No scan step command need be transmitted by the sensecircuitry to the switching circuits for the pen row scan type 1078.

A fifth scan type can be a pen column scan type 1080. The pen columnscan type can be performed in any of a number of bank IDs. Thus, the pencolumn scan type 1080 can be implemented with a command indicating thepen column scan type is to be performed, followed by one or morecommands indicating respective bank IDs in which the pen column scan isto be performed. No scan step command need be transmitted by the sensecircuitry to the switching circuits for the pen column scan type 1080.

In some examples, rather than the PMBs in the switching circuits of thedisclosure including switches corresponding to sense channels to beutilized during the various touch screen scans of the touch screen(e.g., as described with reference to FIG. 9A), the PMBs can includeswitches that correspond instead to scan types to be implemented duringthe various touch screen scans of the touch screen. FIG. 11A illustratesan exemplary switching circuit 1106 configuration in which PMBs 1118a-1118N (referred to collectively as 1118) include switches thatcorrespond to scan types according to examples of the disclosure.Switching circuit 1106 can correspond to any of the switching circuitsdescribed in this disclosure, including switching circuit 506 in FIG.5B, switching circuits 706 in FIGS. 7A-7C and/or switching circuits 806in FIGS. 8A-8D.

Switching circuit 1106 can include pixel mux blocks (“PMBs”) 1118. EachPMB can be coupled to a particular touch node electrode on the touchscreen of the disclosure (not illustrated). For example, PMB 1118 a canbe coupled to touch node electrode 1, PMB 1118 b can be coupled to touchnode electrode 2, and PMB 1118N can be coupled to touch node electrodeN. For the purposes of this disclosure, touch node electrodes can benumbered from top to bottom, then from left to right, on the touchscreen, as illustrated in FIG. 9B, though it is understood that theparticular numbering scheme used can be modified within the scope ofthis disclosure. Thus, moving from PMB 1118 a to PMB 1118 b (i.e.,moving horizontally to the right across switching circuit 1106) cancorrespond to moving from touch node electrode 1 to touch node electrode2 (i.e., moving vertically downwards across the touch screen). There canbe as many PMBs 1118 in switching circuit 1106 as there are touch nodeelectrodes to which the switching circuit is coupled. Further, each PMB1118 can be assigned a bank ID in association withsupernode-identification on the touch screen, similar to as describedwith reference to FIG. 9A. These bank IDs can be stored or hardcoded ineach PMB 1118 itself (not illustrated).

Sense circuitry 1108 can be coupled to switching circuit 1106 at lines1102. Each of lines 1102 can be coupled to a respective one of lines1142 a-1142N (referred to collectively as 1142) and 1144 a-1144 c(referred to collectively as 1144) in interconnect matrix 1140. Lines1142 and 1144 can correspond to interconnect lines 820, 822, 830, 832,840, 842, 844, 850, 852 and/or 854 in FIGS. 8A-8D, for example. Lines1142 and 1144 can carry any number of signals to and/or from sensecircuitry 1108. For example, lines 1142 can be coupled to particularsense channels in sense circuitry 1108. Three such lines are illustratedin FIG. 11A—line 1142 a, which can be coupled to sense channel 1; line1142 b, which can be coupled to sense channel 2; and line 1142N, whichcan be coupled to sense channel N—though it is understood that adifferent number of lines may be utilized. Lines 1144 can be coupled toa common voltage source (e.g., a Vcom voltage source) in sense circuitry1108, a Vbias voltage source (e.g., as described with reference to FIGS.6A-6D) in the sense circuitry, and/or a Vdrive voltage source (e.g., asdescribed with reference to FIGS. 6A-6D) in the sense circuitry. Forexample, line 1144 a can be coupled to a Vdrive voltage source in thesense circuitry, line 1144 b can be coupled to a Vbias voltage source inthe sense circuitry, and line 1144 c can be coupled to a Vcom voltagesource in the sense circuitry. Together, lines 1142 and 1144 can form aninterconnect matrix 1140 via which PMBs 1118 can get access to (i.e., becoupled to) sense channels or signals in sense circuitry 1108.

PMBs 1118 can include a number of switches (e.g., switches 1122 a-1122g, referred to collectively as 1122, in PMB 1118 a). One end of switches1122 can be coupled to the touch node electrode to which the PMB 1118 iscoupled. The other ends of switches 122 can be coupled to lines that canbe coupled to respective ones of lines 1142 and 1144. As statedpreviously, some of switches 1122 can correspond to scan types to beimplemented on the touch screen, and others of the switches cancorrespond to signals to be utilized during the various touch screenscans of the touch screen. For example, switches 1122 e, 1122 f and 1122g can correspond to signals on lines 1144 (e.g., Vcom, Vbias and Vdrivesignals). Specifically, switch 1122 e can be coupled to a line that iscoupled to line 1144 a, switch 1122 f can be coupled to a line that iscoupled to line 1144 c, and switch 1122 g can be coupled to a line thatis coupled to line 1144 b. Thus, if switch 1122 e is closed, touch nodeelectrode 1 can be coupled to line 1144 a, and thus to a Vdrive signal.Similarly, if switch 1122 f is closed, touch node electrode 1 can becoupled to line 1144 c, and thus to a Vcom signal. Finally, if switch1122 g is closed, touch node electrode 1 can be coupled to line 1144 b,and thus to a Vbias signal. The configuration of switches correspondingto switches 1122 e, 1122 f and 1122 g in other PMBs (e.g., PMBs 1118 bthrough 1118N) can be the same as that of switches 1122 e, 1122 f and1122 g in PMB 1118 a. Thus, switches 1122 e, 1122 f and 1122 g can bereferred to as “global signal switches.”

The remaining switches in PMB 1118 a (e.g., switches 1122 a, 1122 b,1122 c and 1122 d) can be scan type dependent switches, and can bereferred to as “scan type switches.” Specifically, the configuration ofthe lines to which switches 1122 a, 1122 b, 1122 c and 1122 d arecoupled can depend on the touch screen scans that are to be implementedon the touch screen with which switching circuit 1106 is utilized, andthe particular configuration that a respective touch node electrode thatis coupled to PMB 1118 a will have during those touch screen scans. Forexample, switch 1122 a can be a pen row scan switch that can be closedwhen the touch node electrode to which PMB 1118 a is coupled (e.g.,touch node electrode 1) is to be utilized in a pen row scan. During apen row scan, touch node electrode 1 can be coupled to sense channel 1in sense circuitry 1108, as illustrated in FIG. 6B. Thus, the line ininterconnect matrix 1140 to which switch 1122 a is coupled can be line1142 a, which, as described previously, can be coupled to sense channel1 in sense circuitry 1108. In other words, the pen row scanconfiguration of PMB 1118 a (and thus touch node electrode 1) can behardcoded in interconnect matrix 1140. In this way, to implement a penrow scan that includes touch node electrode 1, pen row scan switch 1122a in PMB 1118 a need only be closed, and touch node electrode 1 can havethe proper configuration for performing a pen row scan. Sense circuitry1108 can then perform a pen row scan including touch node electrode 1.

In manners similar to above, switch 1122 b can be a pen column scanswitch that can be closed when the touch node electrode to which PMB1118 a is coupled (e.g., touch node electrode 1) is to be utilized in apen column scan, switch 1122 c can be a pen detect scan switch that canbe closed when the touch node electrode to which PMB 1118 a is coupledis to be utilized in a pen detection scan, and switch 1122 d can be adrive/sense switch that can be closed when the touch node electrode towhich PMB 1118 a is coupled is to be utilized in a drive and/or sensescan (e.g., in a scan in which the touch node electrode is to be drivenand sensed to detect the self-capacitance of the touch node electrode,or simply sensed to detect a mutual capacitance of the touch nodeelectrode with respect to another electrode). As above, the lines ininterconnect matrix 1140 to which switches 1122 b, 1122 c and 1122 d arecoupled can be hardcoded based on the various configurations that touchnode electrode 1 is to have during the various scan types with which theswitches correspond. For example, pen column scan switch 1122 b can becoupled to line 1142 a in interconnect matrix 1140, because during a pencolumn scan of the supernode in which touch node electrode 1 isincluded, touch node electrode 1 can be coupled to sense channel 1 insense circuitry 1108, as illustrated in FIG. 6B. Pen detect scan switch1122 c can also be coupled to line 1142 a in interconnect matrix 1140,because during a pen detection scan of the supernode in which touch nodeelectrode 1 is included, touch node electrode 1 can be coupled to sensechannel 1 in sense circuitry 1108, as illustrated in FIG. 6B. Finally,drive/sense switch 1122 d can be coupled to line 1142 a in interconnectmatrix 1140, because during a self-capacitance or mutual capacitancescan of the touch screen, touch node electrode 1 can be coupled to sensechannel 1 in sense circuitry 1108 (e.g., as illustrated in FIGS. 6B and10A). Thus, switches 1122 in PMB 1118 a, and the lines 1142 or 1144 ininterconnect matrix 1140 to which the switches are coupled, canfacilitate the proper configuration of touch node electrode 1 in thescans that are to be implemented on the touch screen of the disclosure.

Switches 1124 a-1124 g (referred to collectively as 1124) in PMB 1118 b,and the lines 1142 or 1144 in interconnect matrix 1140 to which theswitches are coupled, can similarly be configured to facilitate theproper configuration of the touch node electrode to which the PMB iscoupled (e.g., touch node electrode 2) in the scans that are to beimplemented on the touch screen of the disclosure. In the exampleillustrated in FIG. 11A, switches 1124 can be configured in the same wayas switches 1122, except that pen row switch 1124 a can be coupled toline 1142 b in interconnect matrix 1140, and thus can be coupled tosense channel 2 in sense circuitry 1108. In other words, touch nodeelectrode 2 can be coupled to the same sense channels or signals astouch node electrode 1 during touch screen scans that are to beperformed on touch node electrode 2, except for during a pen row scan inwhich touch node electrode 2 can be coupled to sense channel 2 insteadof sense channel 1. The switches on remaining PMBs 1118 can analogouslybe configured to facilitate proper configuration of the touch nodeelectrodes to which the PMBs are coupled during the various scans to beimplemented on the touch screen of the disclosure.

Similar to as described above with reference to FIG. 9A, sense circuitry1108 can transmit touch screen scan information to switching circuit1106 via interface 1104. Interface 1104 can be any interface (e.g., aserial peripheral interface (SPI)) that can allow for communicationbetween sense circuitry 1108 and switching circuit 1106. The touchscreen scan information transmitted by sense circuitry 1108 to switchingcircuit 1106 can be used by interface 1104 and/or PMB logic 1120 a-1120N(referred to collectively as 1120) to control the states of the switcheson the PMBs 1118 (e.g., switches 1122, 1124), and thus to configure thetouch screen to implement the desired touch screen scan. Any appropriatecommand or control signal structure can be utilized for communicationbetween sense circuitry 1108 and interface 1104, and any appropriatelogic can be utilized in interface 1104 and/or PMB logic 1120 tofacilitate proper control of switches 1122, 1124 in PMBs 1118. In someexamples, the command structure for controlling switching circuit 1106in FIG. 11A can be similar to the command structure for controllingswitching circuit 906 in FIG. 9A, as previously described. In someexamples, each PMB 1118 can contain two shift registers and two shadowregisters, represented by 1121 (e.g., 1121A, 1121B and 1121N in FIG.11A). The shift registers 1121 of the PMBs 1118 can be connectedtogether to form a long shift register, as illustrated in FIG. 11A, thecontents of which can be used to control the states of switches in thePMBs. Specifically, shift register 1121A can be connected to shiftregister 1121B, which can be connected to shift registers in other PMBs1118 through to PMB 1118N. A transfer to interface 1104 can be framed bya low chip select signal assertion, and can load the PMB shift register1121. At a rising edge of the chip select, the shift register 1121contents can be loaded into a shadow register in the PMBs 1118, whichcan contain the mode bits shown in column 1156 illustrated in FIG. 11C.Such operation can allow the shadow registers to retain the PMB statewhile loading the shift registers 1121 with new data via the interface1104 (e.g., providing for pipelined operation).

FIG. 11B illustrates an exemplary logic structure for interface 1104 andPMB logic 1120 for implementing pen row and pen column scans on thetouch screen according to examples of the disclosure. In this example,sensing circuitry 1108 can provide various control signals to switchingcircuit 1106 to control its operation—namely, a mode signal 1181, a bankID signal 1183 and a chip select signal 1185. The mode signal 1181 canbe a two bit number, and can specify whether the touch screen scan to beimplemented is a pen row scan or a pen column scan. A mode signal 1181of “10” can indicate a pen row scan, and a mode signal of “11” canindicate a pen column scan, for example. The bank ID signal 1183 canindicate the bank ID of the supernode in which the pen row or pen columnscan is to be implemented. The chip select signal 1185 can be utilizedby PMB logic 1120 for timing purposes, as mentioned above, and as willbe described below.

In interface 1104, comparator 1180 can compare the mode signal 1181 with“10” or “11” (corresponding to a pen row or pen column scan, asdiscussed above). If the mode signal 1181 is “10” or “11”, comparator1180 can enable shift register 1182, which can take the bank IDindicated by the bank ID signal 1183 as its value (i.e., the value ofthe bank ID signal 1183 can be loaded onto the shift register). In PMBlogic 1120, comparator 1184 can, similar to comparator 1180, compare themode signal 1181 with “10” or “11”. If the mode signal 1181 is “10” or“11”, comparator 1184 can transmit to bank flop 1188 the switch controlinformation for the switches in the PMB (e.g., switches 1122 or 1124).In parallel, comparator 1186 can compare the bank ID stored by shiftregister 1182 with the bank ID of the PMB in which PMB logic 1120 isincluded (e.g., PMB 1118 a). If the bank ID stored by shift register1182 matches the bank ID of the PMB in which PMB logic 1120 is included,then comparator 1186 can output a positive (or high) signal to “and”logic 1190. When the chip select signal 1185 is also positive (or high),“and” logic 1190 can output a positive (or high) signal to bank flop1188, which, in response, can output the switch control information tothe switches in the PMB (e.g., switches 1122 or 1124). The switches inthe PMB (e.g., switches 1122 or 1124) can then be configured based onthe switch control information in order to implement the pen row or pencolumn scan instructed by the sense circuitry.

FIG. 11B illustrates an exemplary logic structure for implementing penrow and pen column scans on the touch screen. It is understood thatother logic can be included in interface 1104 and/or PMB logic 1120 forimplementing other scan configurations on the touch screen (e.g., scanconfigurations as described with reference to FIGS. 6A-6D). FIG. 11Cillustrates exemplary states of switches in PMBs 1118 in correspondenceto various control signals received by switching circuit 1106 from sensecircuitry 1108 according to examples of the disclosure. The exemplarystates of switches in PMBs 1118 illustrated in FIG. 11C can result fromappropriate logic operating on various control signals received fromsense circuitry 1108—this logic can be included in interface 1104 and/orPMB logic 1120.

Sense circuitry 1108 can transmit four signals to switching circuit1106: a Vcom enable signal 1150, a Vbias enable signal 1152, a bank IDsignal 1154 (e.g., via a SPI) and a 2bit mode signal 1156. Bank IDsignal 1154 in FIG. 11C can correspond to bank ID signal 1183 in FIG.11B, and mode signal 1156 in FIG. 11C can correspond to mode signal 1181in FIG. 11B. Bank_latch signal 1158 can be generated internally inswitching circuit 1106 when the bank ID signal 1154 matches theprogrammed bank ID for a given PMB. When Vcom enable signal 1150 ishigh, the switch enable state of the Vcom switch (e.g., switch 1122 f inFIG. 11A) can be high—thus the Vcom switch can be closed—regardless ofthe values of the other control signals.

When Vcom enable signal 1150 is low, and Vbias enable signal 1152 ishigh, the switch enable state of the Vbias switch (e.g., switch 1122 gin FIG. 11A) can be high—thus the Vbias switch can be closed—regardlessof the values of the other control signals.

A mode signal 1156 of “00” can signify a self-capacitance or mutualcapacitance scan configuration. When Vcom enable signal 1150 and Vbiasenable signal 1152 are low, and mode signal 1156 is “00”, the switchenable states of the drive/sense switch (e.g., switch 1122 d in FIG.11A), the Vdrive switch (e.g., switch 1122 e in FIG. 11A) and the Vbiasswitch (e.g., switch 1122 g in FIG. 11A) can be high or low depending onwhether the self-capacitance or mutual capacitance scan is beingimplemented, and if self-capacitance, which step of the self-capacitancescan is being implemented. The details of exemplary self-capacitance andmutual capacitance scans were described with reference to FIGS. 6A-6D.

A mode signal 1156 of “01” can signify a pen detection scanconfiguration. When Vcom enable signal 1150 and Vbias enable signal 1152are low, and mode signal 1156 is “01”, the switch enable state of thepen detect switch (e.g., switch 1122 c in FIG. 11A) can be high—thus thepen detect switch can be closed—regardless of the values of the othercontrol signals.

A mode signal 1156 of “10” can signify a pen row scan configuration.When Vcom enable signal 1150 and Vbias enable signal 1152 are low, modesignal 1156 is “10”, and bank ID signal 1154 matches the bank ID of therelevant PMB, the switch enable state of the pen row switch in that PMB(e.g., switch 1122 a in FIG. 11A) can be high—thus the pen row switchcan be closed. Further, the bank_latch signal 1158 can be high for thosePMBs in which pen row scans are to be performed, and low for others.

Finally, a mode signal 1156 of “11” can signify a pen column scanconfiguration. When Vcom enable signal 1150 and Vbias enable signal 1152are low, mode signal 1156 is “11”, and bank ID signal 1154 matches thebank ID of the relevant PMB, the switch enable state of the pen columnswitch in that PMB (e.g., switch 1122 b in FIG. 11A) can be high—thusthe pen column switch can be closed. Further, the bank_latch signal 1158can be high for those PMBs in which pen column scans are to beperformed, and low for others.

The relationships described above between various control signals andvarious switch enable states of PMB switches are exemplary only, and donot limit the scope of the disclosure.

In some examples, the configurations of touch node electrodes (and thusthe configurations of the PMBs to which the touch node electrodes arecoupled) in one scan period or step can mirror the configurations ofother touch node electrodes in another scan period or step. For example,FIG. 12A illustrates an exemplary first scan step of a self-capacitancescan type performed in region 1204 of touch screen 1200 during a firsttime period according to examples of the disclosure. The configurationof touch node electrodes 1202 in region 1204 of touch screen 1200 can besimilar to as described with reference to FIG. 10A.

FIG. 12B illustrates an exemplary first scan step of a self-capacitancescan type performed in region 1206 of touch screen 1200 during a secondtime period according to examples of the disclosure. As is evident fromFIGS. 12A and 12B, the configuration of touch node electrodes 1202 inregion 1206 of touch screen 1200 in FIG. 12B mirrors the configurationof the touch node electrodes in region 1204 of the touch screen in FIG.12A. Therefore, in some examples, instead of requiring the sensecircuitry to transmit touch screen scan information to switchingcircuits during the first time period (e.g., illustrated in FIG. 12A)and during the second time period (e.g., as illustrated in FIG. 12B),sense circuitry can transmit the touch screen scan information onceduring the first time period, and the resulting switch configurationinformation of the switches in the PMBs corresponding to the touch nodeelectrodes 1202 in region 1204 can be shifted down to region 1206 oftouch screen 1200 during the second time period. PMBs corresponding tothe touch node electrodes 1202 in region 1206 can then utilize thatswitch control information that was shifted down to configure their ownswitches. Thus, sense circuitry can be required to transmit lessinformation to the switching circuits than it otherwise may have, andcommunication overhead between the sense circuitry and the switchingcircuits can be reduced.

In some examples, the above-described shifting of switch controlinformation can be performed by shifting the switch control informationfrom one set of PMBs to another set of PMBs. FIG. 12C illustratesexemplary shifting of switch control information from one PMB 1218 toanother PMB according to examples of the disclosure. PMBs 1218 a-1218N(referred to collectively as 1218) can be coupled to touch nodeelectrodes 1202 a-1202N (referred to collectively as 1202), aspreviously described. At time t0, the switches in PMB 1218 a can beconfigured to be in a particular state (e.g., state “A”). Thus, touchnode electrode 1202 a, to which PMB 1218 a can be coupled, can be saidto be configured to be in state A. State A is provided for ease ofdescription, but it is understood that state A can correspond to anyconfiguration of a touch node electrode 1202 as described in thisdisclosure, such as a touch node electrode being coupled to a particularsense channel in sense circuitry.

The configuration of touch node electrode 1202 a can be shifted down totouch node electrode 1202 b by shifting the configuration of PMB 1218 ato PMB 1218 b. In some examples, PMB 1218 a can itself shift itsconfiguration over to PMB 1218 b. In some examples, PMB 1218 a can shiftits configuration over to PMB 1218 b in response to a particular “shift”command received from sense circuitry. If PMB 1218 a were to shift itsconfiguration over to PMB 1218 b, at time t1, touch node electrode 1202b would be configured to be in state A. This type of shifting of stateconfiguration can continue through touch node electrode 1202N and PMB1218N, as illustrated at time tN. In this way, the configurations oftouch node electrodes 1202 and PMBs 1218 can be shifted from one touchnode electrode or PMB to another, rather than those configurationsneeding to be provided from sense circuitry in each instance. In someexamples, configuration information can be shifted by more than one PMBat a time, though single-PMB shifts are provided for ease ofdescription. Referring back to FIGS. 12A and 12B, the touch nodeelectrode 1202 configurations in region 1204 of touch screen 1200 can beshifted down in the manner described above to region 1206 of the touchscreen by shifting the configuration of each touch node electrode downby four touch node electrodes on the touch screen. In some examples,this shift can correspond to shifting the configuration information ofPMBs to the right by four PMBs. Such shifting of configurationinformation can be performed using shift registers that can be includedin the PMBs, as discussed with reference to FIG. 11A, for example.

Thus, the examples of the disclosure provide a flexible systemarchitecture for use in a self-capacitance and mutual capacitance touchsensing system.

Therefore, according to the above, some examples of the disclosure aredirected to a switching circuit comprising: a plurality of pixel muxblocks, each of the pixel mux blocks configured to be coupled to arespective touch node electrode on a touch sensor panel, and each of thepixel mux blocks including logic circuitry; and a plurality of signallines configured to be coupled to sense circuitry, at least one of thesignal lines configured to transmit a touch signal from one of therespective touch node electrodes to the sense circuitry, wherein thelogic circuitry in each pixel mux block of the plurality of pixel muxblocks is configured to control the respective pixel mux block so as toselectively couple the respective pixel mux block to any one of theplurality of signal lines. Additionally or alternatively to one or moreof the examples disclosed above, in some examples, each of the pixel muxblocks further includes a plurality of switches coupled to therespective touch node electrodes, and controlling the respective pixelmux block so as to selectively couple the respective pixel mux block toany one of the plurality of signal lines comprises controlling thestates of the plurality of switches. Additionally or alternatively toone or more of the examples disclosed above, in some examples, theswitching circuit further comprises: a memory including switch controlinformation for controlling the plurality of switches in each pixel muxblock, wherein the logic circuitry in each pixel mux block is coupled tothe memory. Additionally or alternatively to one or more of the examplesdisclosed above, in some examples, the logic circuitry in each pixel muxblock controls the plurality of switches in each pixel mux block basedon the switch control information. Additionally or alternatively to oneor more of the examples disclosed above, in some examples, the memory isconfigured to be populated with the switch control information by thesense circuitry. Additionally or alternatively to one or more of theexamples disclosed above, in some examples, each of the plurality ofswitches is coupled to one of the plurality of signal lines.Additionally or alternatively to one or more of the examples disclosedabove, in some examples, a first switch of the plurality of switches iscoupled to a first signal line of the plurality of signal lines, and asecond switch of the plurality of switches is coupled to the firstsignal line of the plurality of signal lines. Additionally oralternatively to one or more of the examples disclosed above, in someexamples, the sense circuitry is configured to perform a plurality oftouch sensor panel scans on the touch sensor panel, and each of theplurality of switches is coupled to one of the plurality of signal linesin correspondence to configurations of the plurality of touch sensorpanel scans. Additionally or alternatively to one or more of theexamples disclosed above, in some examples, the logic circuitry in eachpixel mux block is configured to control the respective pixel mux blockso as to selectively couple the respective pixel mux block to any of theplurality of signal lines in response to control provided by the sensecircuitry. Additionally or alternatively to one or more of the examplesdisclosed above, in some examples, at least one of the signal lines isconfigured to be coupled to the sense circuitry via a shared trace thatis shared with at least another signal line included in anotherswitching circuit coupled to the touch sensor panel. Additionally oralternatively to one or more of the examples disclosed above, in someexamples, the shared trace is disposed on a flex connector configured tocouple the switching circuit to the sense circuitry. Additionally oralternatively to one or more of the examples disclosed above, in someexamples, the switching circuit is configured to be coupled to a firstplurality of touch node electrodes that are part of a supernode on thetouch sensor panel, and the other switching circuit is configured to becoupled to a second plurality of touch node electrodes that are part ofthe supernode on the touch sensor panel. Additionally or alternativelyto one or more of the examples disclosed above, in some examples, theshared trace is configured to transmit a touch signal from the supernodeto the sense circuitry. Additionally or alternatively to one or more ofthe examples disclosed above, in some examples, the switching circuitfurther comprises a second plurality of signal lines, wherein: theplurality of signal lines comprise a first plurality of signal lines,the first plurality of signal lines is configured to be coupled to afirst set of touch node electrodes on the touch sensor panel, the secondplurality of signal lines is configured to be coupled to a second set oftouch node electrodes on the touch sensor panel, and a first end of thefirst plurality of signal lines is disposed adjacent to a second end ofthe second plurality of signal lines. Additionally or alternatively toone or more of the examples disclosed above, in some examples, a numberof signal lines in the first plurality of signal lines is the same as anumber of signal lines in the second plurality of signal lines.Additionally or alternatively to one or more of the examples disclosedabove, in some examples, the first plurality of signal lines isconfigured to be coupled to a first plurality of sense channels in thesense circuitry, and the second plurality of signal lines is configuredto be coupled to a second plurality of sense channels in the sensecircuitry. Additionally or alternatively to one or more of the examplesdisclosed above, in some examples, the switching circuit has a firstdimension, the first plurality of signal lines extend across a firstportion of the switching circuit along the first dimension, and thesecond plurality of signal lines extend across a second portion of theswitching circuit along the first dimension.

Some examples of the disclosure are directed to a method of operating atouch screen, the method comprising: coupling each of a plurality ofpixel mux blocks to a respective touch node electrode on a touch sensorpanel; transmitting a touch signal on at least one of a plurality ofsignal lines from one of the respective touch node electrodes to sensecircuitry; and selectively coupling each pixel mux block to any one ofthe plurality of signal lines. Additionally or alternatively to one ormore of the examples disclosed above, in some examples, selectivelycoupling each pixel mux block to any one of the plurality of signallines is based on switch control information included on a memory.Additionally or alternatively to one or more of the examples disclosedabove, in some examples, the method further comprises populating thememory with the switch control information by the sense circuitry.

Some examples of the disclosure are directed to a switching circuitcomprising: a plurality of pixel mux blocks including a first pluralityof pixel mux blocks and a second plurality of pixel mux blocks, eachpixel mux block of the plurality of pixel mux blocks configured toselectively couple a respective touch node electrode on a touch sensorpanel to sense circuitry, wherein the first plurality of pixel muxblocks is associated with a first group identification, and the secondplurality of pixel mux blocks is associated with a second groupidentification, different from the first group identification; and logiccircuitry included in each pixel mux block of the first plurality ofpixel mux blocks and the second plurality of pixel mux blocks, the logiccircuitry configured to configure its respective pixel mux block basedon a group identification of its respective pixel mux block and a targetgroup identification provided by the sense circuitry. Additionally oralternatively to one or more of the examples disclosed above, in someexamples, the logic circuitry is configured to: in accordance with adetermination that the target group identification corresponds to therespective group identification of the respective pixel mux blockcorresponding to the logic circuitry, configuring the respective pixelmux block to couple the respective touch node electrode corresponding tothe respective pixel mux block to a first signal line; and in accordancewith a determination that the target group identification does notcorrespond to the respective group identification of the respectivepixel mux block, configuring the respective pixel mux block to decouplethe respective touch node electrode corresponding to the respectivepixel mux block from the first signal line. Additionally oralternatively to one or more of the examples disclosed above, in someexamples, the target group identification corresponds to the first groupidentification, the pixel mux blocks in the first plurality of pixel muxblocks are configured in a first scan configuration, and the pixel muxblocks in the second plurality of pixel mux blocks are configured in asecond scan configuration, different from the first scan configuration.Additionally or alternatively to one or more of the examples disclosedabove, in some examples, the first scan configuration comprises a penscan configuration, and the second scan configuration does not comprisea pen scan configuration.

Although examples of this disclosure have been fully described withreference to the accompanying drawings, it is to be noted that variouschanges and modifications will become apparent to those skilled in theart. Such changes and modifications are to be understood as beingincluded within the scope of examples of this disclosure as defined bythe appended claims.

1. A switching circuit comprising: a plurality of signal linesconfigured to be coupled to sense circuitry, at least one of the signallines configured to transmit a touch signal from one or more touchelectrodes on a touch sensor panel to the sense circuitry; and aplurality of pixel mux blocks, each of the pixel mux blocks configuredto be coupled to different respective touch electrodes on the touchsensor panel, and each of the pixel mux blocks including one or moreswitches corresponding to different scan types to be performed on thetouch sensor panel, wherein the plurality of pixel mux blocks includes:a first pixel mux block configured to be coupled to a first touchelectrode and receive a scan type control signal that indicates a scantype according to which the touch sensor panel is operating, wherein:the first pixel mux block includes a first set of switches configured toselectively couple the first touch electrode to a first set of signallines; and a first switch of the first set of switches corresponds to afirst scan type and is configured to selectively couple the first touchelectrode to the first signal line of the first set of signal linesbased on the scan type control signal indicating that the touch sensorpanel is operating according to the first scan type; and a second pixelmux block configured to be coupled to a second touch electrode andreceive the scan type control signal, wherein: the second pixel muxblock includes a second set of switches configured to selectively couplethe second touch electrode to a second set of signal lines, differentfrom the first set of signal lines; and a first switch of the second setof switches corresponds to the first scan type and is configured toselectively couple the second touch electrode to a first signal line ofthe second set of signal lines, different from the first signal line ofthe first set of signal lines, based on the scan type control signalindicating that the touch sensor panel is operating according to thefirst scan type.
 2. The switching circuit of claim 1, furthercomprising: first logic in the first pixel mux block, the first logicconfigured to: in accordance with the scan type control signalindicating that the touch sensor panel is operating according to thefirst scan type, cause the first switch to couple the first touchelectrode to the first signal line of the first set of signal lines; andin accordance with the scan type control signal indicating that thetouch sensor panel is not operating according to the first scan type,cause the first switch to decouple the first touch electrode from thefirst signal line of the first set of signal lines; and second logic inthe second pixel mux block, the second logic configured to: inaccordance with the scan type control signal indicating that the touchsensor panel is operating according to the first scan type, cause thesecond switch to couple the second touch electrode to the first signalline of the second set of signal lines; and in accordance with the scantype control signal indicating that the touch sensor panel is notoperating according to the first scan type, cause the second switch todecouple the second touch electrode from the first signal line of thesecond set of signal lines.
 3. The switching circuit of claim 2, furthercomprising: a second switch of the first set of switches correspondingto a second scan type, different than the first scan type, the secondswitch of the first set of switches coupled to a second signal line ofthe first set of signal lines; and a second switch of the second set ofswitches corresponding to the second scan type, the second switch of thesecond set of switches coupled to a second signal line of the second setof signal lines, wherein: the first logic is further configured to, inaccordance with the scan type control signal indicating that the touchsensor panel is operating according to the second scan type, cause thesecond switch of the first set of switches to couple the first touchelectrode to the second signal line of the first set of signal lines,and the second logic is further configured to, in accordance with thescan type control signal indicating that the touch sensor panel isoperating according to the second scan type, cause the second switch ofthe second set of switches to couple the second touch electrode to thesecond signal line of the second set of signal lines.
 4. The switchingcircuit of claim 3, wherein the second signal line of the first set ofsignal lines and the second signal line of the second set of signallines are a same signal line.
 5. The switching circuit of claim 3,wherein the second signal line of the first set of signal lines and thesecond signal line of the second set of signal lines are differentsignal lines.
 6. The switching circuit of claim 1, wherein: the firstpixel mux block is associated with a respective group identification,the second pixel mux block is associated with a respective groupidentification, the scan type control signal further indicates a targetgroup identification, the first switch of the first set of switches isconfigured to selectively couple the first touch electrode to the firstsignal line of the first set of signal lines based further on the targetgroup identification indicated in the scan type control signal, and thefirst switch of the second set of switches is configured to selectivelycouple the second touch electrode to the first signal line of the secondset of signal lines based further on the target group identificationindicated in the scan type control signal.
 7. The switching circuit ofclaim 6, wherein: the first switch of the first set of switches isconfigured to: in accordance with a determination that the target groupidentification corresponds to the respective group identification of thefirst pixel mux block, couple the first touch electrode corresponding tothe first pixel mux block to the first signal line of the first set ofsignal lines, and in accordance with a determination that the targetgroup identification does not correspond to the respective groupidentification of the first pixel mux block, decouple the first touchelectrode corresponding to the first pixel mux block from the firstsignal line of the first set of signal lines, and the first switch ofthe second set of switches is configured to: in accordance with adetermination that the target group identification corresponds to therespective group identification of the second pixel mux block, couplethe second touch electrode corresponding to the second pixel mux blockto the first signal line of the second set of signal lines, and inaccordance with a determination that the target group identificationdoes not correspond to the respective group identification of the secondpixel mux block, decouple the second touch electrode corresponding tothe second pixel mux block from the first signal line of the second setof signal lines.
 8. The switching circuit of claim 7, wherein the firstscan type comprises a pen detection scan type.
 9. The switching circuitof claim 1, wherein: the first set of signal lines includes a firstsignal line of the plurality of signal lines and a second signal line ofthe plurality of signal lines; and the second set of signal linesincludes the second signal line of the plurality of signal lines anddoes not include the first signal line of the plurality of signal lines.10. The switching circuit of claim 1, wherein: the first set of switchesis hard coded to selectively couple the first touch electrode to thefirst set of signal lines; and the second set of switches is hard codedto selectively couple the second touch electrode to the second set ofsignal lines.
 11. A method of operating a switching circuit thatincludes a plurality of signal lines configured to be coupled to sensecircuitry, at least one of the signal lines configured to transmit atouch signal from one or more touch electrodes on a touch sensor panelto the sense circuitry, the method comprising: receiving, at a firstpixel mux block configured to be coupled to a first touch electrode onthe touch sensor panel, a scan type control signal that indicates a scantype according to which the touch sensor panel is operating, wherein thefirst pixel mux block includes a first set of switches configured toselectively couple the first touch electrode to a first set of signallines; selectively coupling, with a first switch of the first set ofswitches corresponding to a first scan type, the first touch electrodeto a first signal line of the first set of signal lines based on thescan type control signal indicating that the touch sensor panel isoperating according to the first scan type; receiving, at a second pixelmux block configured to be coupled to a second touch electrode on thetouch sensor panel, the scan type control signal, wherein the secondpixel mux block includes a second set of switches configured toselectively couple the second touch electrode to a second set of signallines, different from the first set of signal lines; and selectivelycoupling, with a first switch of the second set of switchescorresponding to the first scan type, the second touch electrode to afirst signal line of the second set of signal lines, different than thefirst signal line of the first set of signal lines, based on the scantype control signal indicating that the touch sensor panel is operatingaccording to the first scan type.
 12. The method of claim 11, furthercomprising: in accordance with the scan type control signal indicatingthat the touch sensor panel is operating according to the first scantype: coupling, with the first switch of the first set of switches, thefirst touch electrode to the first signal line of the first set ofsignal lines; and coupling, with the first switch of the second set ofswitches, the second touch electrode to the first signal line of thesecond set of signal lines; and in accordance with the scan type controlsignal indicating that the touch sensor panel is not operating accordingto the first scan type: decoupling, with the first switch of the firstset of switches, the first touch electrode from the first signal line ofthe first set of signal lines; and decoupling, with the first switch ofthe second set of switches, the second touch electrode from the firstsignal line of the second set of signal lines.
 13. The method of claim12, further comprising: in accordance with the scan type control signalindicating that the touch sensor panel is operating according to asecond scan type, different than the first scan type: coupling, with asecond switch of the first set of switches corresponding to the secondscan type, the first touch electrode to a second signal line of thefirst set of signal lines; and coupling, with a second switch of thesecond set of switches corresponding to the second scan type, the secondtouch electrode to a second signal line of the second set of signallines.
 14. The method of claim 13, wherein the second signal line of thefirst set of signal lines and the second signal line of the second setof signal lines are a same signal line.
 15. The method of claim 11,further comprising: selectively coupling, using the first switch of thefirst set of switches, the first touch electrode to the first signalline of the first set of signal lines based further on a target groupidentification indicated in the scan type control signal, wherein thefirst pixel mux block is associated with a respective groupidentification; and selectively coupling, using the first switch of thesecond set of switches, the second touch electrode to the first signalline of the second set of signal lines based further on the target groupidentification indicated in the scan type control signal, wherein thesecond pixel mux block is associated with a respective groupidentification.
 16. The method of claim 15, further comprising: inaccordance with a determination that the target group identificationcorresponds to the respective group identification of the first pixelmux block, coupling, with the first switch of the first set of switches,the first touch electrode corresponding to the first pixel mux block tothe first signal line of the first set of signal lines; in accordancewith a determination that the target group identification does notcorrespond to the respective group identification of the first pixel muxblock, decoupling, with the first switch of the first set of switches,the first touch electrode corresponding to the first pixel mux blockfrom the first signal line of the first set of signal lines; inaccordance with a determination that the target group identificationcorresponds to the respective group identification of the second pixelmux block, coupling, with the first switch of the second set ofswitches, the second touch electrode corresponding to the second pixelmux block to the first signal line of the second set of signal lines;and in accordance with a determination that the target groupidentification does not correspond to the respective groupidentification of the second pixel mux block, decoupling, with the firstswitch of the second set of switches, the second touch electrodecorresponding to the second pixel mux block from the first signal lineof the second set of signal lines.
 17. The method of claim 11, wherein:the first set of signal lines includes a first signal line of theplurality of signal lines and a second signal line of the plurality ofsignal lines; and the second set of signal lines includes the secondsignal line of the plurality of signal lines and does not include thefirst signal line of the plurality of signal lines.
 18. The method ofclaim 11, wherein: the first set of switches is hard coded toselectively couple the first touch electrode to the first set of signallines; and the second set of switches is hard coded to selectivelycouple the second touch electrode to the second set of signal lines. 19.A computer-readable storage medium including instructions, which whenexecuted by a processor of a touch sensor panel, cause the touch sensorpanel to perform a method comprising: receiving, at a first pixel muxblock configured to be coupled to a first touch electrode on the touchsensor panel, a scan type control signal that indicates a scan typeaccording to which the touch sensor panel is operating, wherein thefirst pixel mux block includes a first set of switches configured toselectively couple the first touch electrode to a first set of signallines; selectively coupling, with a first switch of the first set ofswitches corresponding to a first scan type, the first touch electrodeto a first signal line of the first set of signal lines based on thescan type control signal indicating that the touch sensor panel isoperating according to the first scan type; receiving, at a second pixelmux block configured to be coupled to a second touch electrode on thetouch sensor panel, the scan type control signal, wherein the secondpixel mux block includes a second set of switches configured toselectively couple the second touch electrode to a second set of signallines, different from the first set of signal lines; and selectivelycoupling, with a first switch of the second set of switchescorresponding to the first scan type, the second touch electrode to afirst signal line of the second set of signal lines, different than thefirst signal line of the first set of signal lines, based on the scantype control signal indicating that the touch sensor panel is operatingaccording to the first scan type.